Full Text Available Abstract Retinitispigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

Gene therapy for dominantly inherited genetic disease is more difficult than gene-based therapy for recessive disorders, which can be treated with gene supplementation. Treatment of dominant disease may require gene supplementation partnered with suppression of the expression of the mutant gene either at the DNA level, by gene repair, or at the RNA level by RNA interference or transcriptional repression. In this review, we examine some of the gene delivery approaches used to treat animal models of autosomal dominant retinitispigmentosa, focusing on those models associated with mutations in the gene for rhodopsin. We conclude that combinatorial approaches have the greatest promise for success. PMID:23077406

RetinitisPigmentosa (RP) is the term used to describe a diverse set of degenerative eye diseases affecting the photoreceptors (rods and cones) in the retina. This work builds on an existing mathematical model of RP that focused on the interaction of the rods and cones. We non-dimensionalize the model and examine the stability of the equilibria. We then numerically investigate other stable modes that are present in the system for various parameter values and relate these modes to the original problem. Our results show that stable modes exist for a wider range of parameter values than the stability of the equilibrium solutions alone, suggesting that additional approaches to preventing cone death may exist.

Retinitispigmentosa (RP) is one of the most common hereditary retinal dystrophies and causes of visual impairment affecting all age groups. The reported incidence varies, but is considered to be between 1 in 3,000 to 1 in 7,000. Sector retinitispigmentosa is an atypical form of RP that is characterized by regionalized areas of bone spicule pigmentation, usually in the inferior quadrants of the retina. A 57-year-old Hispanic man with a history of previously diagnosed retinitispigmentosa came to the clinic with a longstanding symptom of decreased vision at night. Bone spicule pigmentation was found in the nasal and inferior quadrants in each eye. He demonstrated superior and temporal visual-field loss corresponding to the areas of the affected retina. Clinical measurements of visual-field loss, best-corrected visual acuity, and ophthalmoscopic appearance have remained stable during the five years the patient has been followed. Sector retinitispigmentosa is an atypical form of RP that is characterized by bilateral pigmentary retinopathy, usually isolated to the inferior quadrants. The remainder of the retina appears clinically normal, although studies have found functional abnormalities in these areas as well. Sector RP is generally considered a stationary to slowly progressive disease, with subnormal electro-retinogram findings and visual-field defects corresponding to the involved retinal sectors. Management of RP is very difficult because there are no proven methods of treatment. Studies have shown 15,000 IU of vitamin A palmitate per day may slow the progression, though this result is controversial. Low vision rehabilitation, long wavelength pass filters, and pedigree counseling remain the mainstay of management.

Seventeen patients with retinitispigmentosa (RP) have been investigated audiologically. Of 9 found to have a significant hearing loss, 6 were examples of Usher's syndrome; these patients had a cochlear pattern of hearing loss. The other 3 were examples of Senior's syndrome, Kearne-Sayre syndrome and Lawrence-Moon-Biedle syndrome respectively. Two of these patients had absent stapedius reflexes. It is suggested that patients with different RP-deafness syndromes may have lesions in different p...

A patient presented with unilateral findings of night blindness shown by impaired rod function and dark adaptation, constricted visual fields with good central acuity, a barely recordable electro-retinographic b-wave, and a unilaterally impaired electro-oculogram. There were none of the pigmentary changes usually associated with retinitispigmentosa. The unaffected right eye was normal in all respects. Therefore the case is most probably one of unilateral retinitispigmentosa sine pigmento.

Full Text Available Despite mutations in the rod phosphodiesterase 6-alpha (PDE6A gene being well-recognized as a cause of human retinitispigmentosa, no definitive treatments have been developed to treat this blinding disease. We performed a trial of retinal gene augmentation in the Pde6a mutant dog using Pde6a delivery by capsid-mutant adeno-associated virus serotype 8, previously shown to have a rapid onset of transgene expression in the canine retina. Subretinal injections were performed in 10 dogs at 29–44 days of age, and electroretinography and vision testing were performed to assess functional outcome. Retinal structure was assessed using color fundus photography, spectral domain optical coherence tomography, and histology. Immunohistochemistry was performed to examine transgene expression and expression of other retinal genes. Treatment resulted in improvement in dim light vision and evidence of rod function on electroretinographic examination. Photoreceptor layer thickness in the treated area was preserved compared with the contralateral control vector treated or uninjected eye. Improved rod and cone photoreceptor survival, rhodopsin localization, cyclic GMP levels and bipolar cell dendrite distribution was observed in treated areas. Some adverse effects including foci of retinal separation, foci of retinal degeneration and rosette formation were identified in both AAV-Pde6a and control vector injected regions. This is the first description of successful gene augmentation for Pde6a retinitispigmentosa in a large animal model. Further studies will be necessary to optimize visual outcomes and minimize complications before translation to human studies.

Neuroprotection may prevent or forestall the progression of incurable eye diseases, such as retinitispigmentosa, one of the major causes of adult blindness. Decreased cellular ATP levels may contribute to the pathology of this eye disease and other neurodegenerative diseases. Here we describe small compounds (Kyoto University Substances, KUSs) that were developed to inhibit the ATPase activity of VCP (valosin-containing protein), the most abundant soluble ATPase in the cell. Surprisingly, KUSs did not significantly impair reported cellular functions of VCP but nonetheless suppressed the VCP-dependent decrease of cellular ATP levels. Moreover, KUSs, as well as exogenous ATP or ATP-producing compounds, e.g. methylpyruvate, suppressed endoplasmic reticulum stress, and demonstrably protected various types of cultured cells from death, including several types of retinal neuronal cells. We then examined their in vivo efficacies in rd10, a mouse model of retinitispigmentosa. KUSs prevented photoreceptor cell death and preserved visual function. These results reveal an unexpected, crucial role of ATP consumption by VCP in determining cell fate in this pathological context, and point to a promising new neuroprotective strategy for currently incurable retinitispigmentosa. PMID:25096051

textabstractRetinitispigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized by the primary degeneration of rod and cone photoreceptors. RP is a leading cause of visual disability, with a worldwide prevalence of 1:4000. Although the majority of RP cases are non-syndromic,

Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitispigmentosa. This study provides the first clinicopathologic correlations for this form of retinitispigmentosa. A family with autosomal dominant concentric retinitispigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitispigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitispigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective

Full Text Available Purpose: Retinitispigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer of P23H versus SD rat retinas. Conclusions: In the P23H rat model of retinitispigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

Purpose: Retinitispigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes, and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer (GCL) of P23H vs. SD rat retinas. Conclusions: In the P23H rat model of retinitispigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina. PMID:26733810

RetinitisPigmentosa includes a number of inherited diseases which usually result in blindness. The disease is progressive in nature and begins with the deterioration of cells in the eye responsible for peripheral vision. As the condition worsens there is a gradual loss of peripheral vision and night blindness. Proper educational planning requires…

Oxidative stress (OS), which increases during retinal degenerative disorders, contributes to photoreceptor cell loss. The objective of this study was to investigate the changes in the metabolic state of the eye tissue in rodent models of retinitispigmentosa by using the cryofluorescence imaging technique. The mitochondrial metabolic coenzymes NADH and FADH2 are autofluorescent and can be monitored without exogenous labels using optical techniques. The NADH redox ratio (RR), which is the ratio of the fluorescence intensity of these fluorophores (NADH/FAD), was used as a quantitative diagnostic marker. The NADH RR was examined in an established rodent model of retinitispigmentosa (RP), the P23H rat, and compared to that of control Sprague-Dawley (SD) rats and P23H NIR treated rats. Our results demonstrated 24% decrease in the mean NADH RR of the eyes from P23H transgenic rats compared to normal rats and 20% increase in the mean NADH RR of the eyes from the P23H NIR treated rats compared to P23H non-treated rats.

Objective. In clinical trials, retinitispigmentosa patients implanted with a retinal prosthetic device show enhanced spatial vision, including the ability to read large text and navigate. New prosthetics aim to increase spatial resolution by decreasing pixel/electrode size and limiting current spread. To examine spatial resolution of a new prosthetic design, we characterized and compared two photovoltaic array (PVA) designs and their interaction with the retina after subretinal implantation in transgenic S334ter line 3 rats (Tg S334ter-3). Approach. PVAs were implanted subretinally at two stages of degeneration and assessed in vivo using extracellular recordings in the superior colliculus (SC). Several aspects of this interaction were evaluated by varying duration, irradiance and position of a near infrared laser focused on the PVA. These characteristics included: activation threshold, response linearity, SC signal topography and spatial localization. The major design difference between the two PVA designs is the inclusion of local current returns in the newer design. Main results. When tested in vivo, PVA-evoked response thresholds were independent of pixel/electrode size, but differ between the new and old PVA designs. Response thresholds were independent of implantation age and duration (⩽7.5 months). For both prosthesis designs, threshold intensities were within established safety limits. PVA-evoked responses require inner retina synaptic transmission and do not directly activate retinal ganglion cells. The new PVA design evokes local retinal activation, which is not found with the older PVA design that lacks local current returns. Significance. Our study provides in vivo evidence that prosthetics make functional contacts with the inner nuclear layer at several stages of degeneration. The new PVA design enhances local activation within the retina and SC. Together these results predict that the new design can potentially harness the inherent processing within

Full Text Available Introduction. This is an observational case report presenting retinitispigmentosa associated with pseudoexfoliative glaucoma. Case outline. A 69-year-old man presented with retinitispigmentosa. On examination, pseudoexfoliative material was detected on anterior segment structures, and intraocular pressure was 26 mmHg in the right and 24 mmHg in the left eye. The patient was commenced on topical antiglaucomatous therapy (timolol + dorzolamide twice daily, latanoprost once in the evening to both eyes. Conclusion. To the best of our knowledge, this is the first reported case of retinitispigmentosa associated with pseudoexfoliative glaucoma. Although rare, retinitispigmentosa and glaucoma can occur in the same eye.

Retinal detachment and retinal holes in two family members with retinitispigmentosa sine pigmento are reported. We believe these are the first such cases reported in the literature. We describe the presenting symptoms and management, including cryotherapy, scleral buckling procedure, and sulfur hexafluoride injection (SF6), resulting in stable visual acuity in one case and retinal reattachment and improved visual acuity in the other case.

Oxidative stress (OS) and mitochondrial dysfunction contribute to photoreceptor cell loss in retinal degenerative disorders. The metabolic state of the retina in a rodent model of retinitispigmentosa (RP) was investigated using a cryo-fluorescence imaging technique. The mitochondrial metabolic coenzymes nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent and can be monitored without exogenous labels using optical techniques. The cryo-fluorescence redox imaging technique provides a quantitative assessment of the metabolism. More specifically, the ratio of the fluorescence intensity of these fluorophores (NADH/FAD), the NADH redox ratio (RR), is a marker of the metabolic state of the tissue. The NADH RR and retinal function were examined in an established rodent model of RP, the P23H rat compared to that of nondystrophic Sprague-Dawley (SD) rats. The NADH RR mean values were 1.11±0.03 in the SD normal and 0.841±0.01 in the P23H retina, indicating increased OS in the P23H retina. Electroretinographic data revealed a significant reduction in photoreceptor function in P23H animals compared to SD nozrmal rats. Thus, cryo-fluorescence redox imaging was used as a quantitative marker of OS in eyes from transgenic rats and demonstrated that alterations in the oxidative state of eyes occur during the early stages of RP.

Full Text Available Previously we have shown that compacted DNA nanoparticles can drive high levels of transgene expression after subretinal injection in the mouse eye. Here we delivered compacted DNA nanoparticles containing a therapeutic gene to the retinas of a mouse model of retinitispigmentosa. Nanoparticles containing the wild-type retinal degeneration slow (Rds gene were injected into the subretinal space of rds(+/- mice on postnatal day 5. Gene expression was sustained for up to four months at levels up to four times higher than in controls injected with saline or naked DNA. The nanoparticles were taken up into virtually all photoreceptors and mediated significant structural and biochemical rescue of the disease without histological or functional evidence of toxicity. Electroretinogram recordings showed that nanoparticle-mediated gene transfer restored cone function to a near-normal level in contrast to transfer of naked plasmid DNA. Rod function was also improved. These findings demonstrate that compacted DNA nanoparticles represent a viable option for development of gene-based interventions for ocular diseases and obviate major barriers commonly encountered with non-viral based therapies.

By chance, we found a rabbit strain with retinal dystrophy. The eyes of these rabbits were examined by ophthalmoscopy, electroretinography, histology, and cytology--the latter after retina dissociation with papaine. The results suggest this rabbit strain to be a possible animal model for human retinitispigmentosa.

To identify the locus responsible for the blind mutation rdd (retinal dysplasia and degeneration) in chickens and to further characterise the rdd phenotype. The eyes of blind and sighted birds were subjected to ophthalmic, morphometric and histopathological examination to confirm and extend published observations. Electroretinography was used to determine age of onset. Birds were crossed to create pedigrees suitable for genetic mapping. DNA samples were obtained and subjected to a linkage search. Measurement of IOP, axial length, corneal diameter, and eye weight revealed no gross morphological changes in the rdd eye. However, on ophthalmic examination, rdd homozygotes have a sluggish pupillary response, atrophic pecten, and widespread pigmentary disturbance that becomes more pronounced with age. Older birds also have posterior subcapsular cataracts. At three weeks of age, homozygotes have a flat ERG indicating severe loss of visual function. Pathological examination shows thinning of the RPE, ONL, photoreceptors and INL, and attenuation of the ganglion cell layer. From 77 classified backcross progeny, 39 birds were blind and 38 sighted. The rdd mutation was shown to be sex-linked and not autosomal as previously described. Linkage analysis mapped the rdd locus to a small region of the chicken Z chromosome with homologies to human chromosomes 5q and 9p. Ophthalmic, histopathologic, and electrophysiological observations suggest rdd is similar to human recessive retinitispigmentosa. Linkage mapping places rdd in a region homologous to human chromosomes 9p and 5q. Candidate disease genes or loci include PDE6A, WGN1, and USH2C. This is the first use of genetic mapping in a chicken model of human disease.

To study the anamnestic immune response to retinal specific antigens of two patients suffering from a rare triad of retinitispigmentosa, Coats disease and uveitis. 17-year-old girl presented with an acute episode of panuveitis, and her 19-year-old brother suffered from chronic uveitis. On examination, both patients showed retinal vascular changes and subretinal exudations typical of Coats disease, with bone-spicule pigmentary changes as observed in retinitispigmentosa. All routine examinations were unrevealing. However, the peripheral lymphocytes from these two siblings gave a specific anamnestic response to retinal antigens in vitro. A stimulation index of 4.6 was obtained when the sister's lymphocytes were stimulated with interphotoreceptor binding protein, IRBP--during the acute stage of the uveitis. The brother's lymphocytes showed a stimulation index of 2.7 towards S-Ag during the chronic phase of his uveitic condition. These results indicate that autoimmunity towards retinal antigens may play some role in specific types of retinitispigmentosa. Whether these autoimmune reactions are a primary pathological mechanism or are secondary to the extensive destruction of the photoreceptor layer resulting from the retinitispigmentosa remains debatable.

Retinitispigmentosa is a rod-cone dystrophy, commonly genetic in nature. Approximately 60-80% of those with retinitispigmentosa inherit it by an autosomal recessive transmission (Brilliant, 1999). There have been some reported cases with no known family history. The symptoms of retinitispigmentosa are decreased acuity, photophobia, night…

Retinitispigmentosa (RP) is the most common inherited eye disease that usually leads into blind, and is high simplex and clinical heterogeneity. Recent years, some new hereditary forms have been found, such as digenic RP, mitochondrial RP, incomplete dominant inheritance RP. The phenotype of RP is multiplicity. Incompatible phenomenon between genotype and phenotypes was shown in some genes such as peripherin/RDS, RHO, RP2 and RP3. The complicated phenotype was shown in the rare RP forms, such as centricity RP, stemma RP, retinitispigmentosa sine pigmento, and retinal degeneration slow. Retinal transplantation, retinal implantation, drug and neurotrophic factor therapy, and gene therapy have been well studied worldwide and presented some hopeful efficacy. Ophthalmologists and practitioners should cognize the new advance and new knowledge on RP therapy with a scientific view for better serving the RP patients.

Retinitispigmentosa (RP) is a group of inherited diseases characterized by the death of rod photoreceptors, followed by the death of cone photoreceptors, progressively leading to partial or complete blindness. Currently no specific treatment is available for RP patients. Sulforaphane (SFN) has been confirmed to be an effective antioxidant in the treatment of many diseases. In this study, we tested the therapeutic effects of SFN against photoreceptor degeneration in Pde6b rd10 mice. rd10 mice and C57/BL6 wild-type (WT) mice were treated with SFN and saline, respectively, from P6 to P20. Electroretinography (ERG), terminal deoxynucleotidyl transferase dUTP nick end labeling and western blot were tested, respectively, at P21 for the analysis of retinal function, retinal cell apoptosis or death and the protein express of GRP78/BiP (TUNEL) as a marker of endoplasmic reticulum (ER) stress. Compared with the saline group, the SFN-treated group showed significantly higher ERG a-wave and b-wave amplitudes, less photoreceptor death, and the downregulation of GRP78/BiP. Our data showed that SFN ameliorated the retinal degeneration of rd10 mice, which is possibly related to the downregulation of GRP78 expression.

Sectorial retinitispigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, ...

A new test designed to detect an hereditary eye disease called retinitispigmentosa (RP) is described. This condition is revealed by pigmentation in the retina, but early diagnosis is difficult because the symptoms are subtle, and since it is genetically recessive it frequently occurs in families with no history of early blindness. In many cases…

The characteristic features of RP (retinitispigmentosa-an untreatable conditions usually resulting in night blindness) are discussed and functioning considerations in the classroom (including the use of protective devices and mobility aids) are noted. Classroom modifications such as darklined paper and black pens are suggested. (CL)

Full Text Available Abstract Background Retinitispigmentosa is characterized by the sequential loss of rod and cone photoreceptors. The preservation of cones would prevent blindness due to their essential role in human vision. Rod-derived Cone Viability Factor is a thioredoxin-like protein that is secreted by rods and is involved in cone survival. To validate the activity of Rod-derived Cone Viability Factors (RdCVFs as therapeutic agents for treating retinitisPigmentosa, we have developed e-conome, an automated cell counting platform for retinal flat mounts of rodent models of cone degeneration. This automated quantification method allows for faster data analysis thereby accelerating translational research. Methods An inverted fluorescent microscope, motorized and coupled to a CCD camera records images of cones labeled with fluorescent peanut agglutinin lectin on flat-mounted retinas. In an average of 300 fields per retina, nine Z-planes at magnification X40 are acquired after two-stage autofocus individually for each field. The projection of the stack of 9 images is subject to a threshold, filtered to exclude aberrant images based on preset variables. The cones are identified by treating the resulting image using 13 variables empirically determined. The cone density is calculated over the 300 fields. Results The method was validated by comparison to the conventional stereological counting. The decrease in cone density in rd1 mouse was found to be equivalent to the decrease determined by stereological counting. We also studied the spatiotemporal pattern of the degeneration of cones in the rd1 mouse and show that while the reduction in cone density starts in the central part of the retina, cone degeneration progresses at the same speed over the whole retinal surface. We finally show that for mice with an inactivation of the Nucleoredoxin-like genes Nxnl1 or Nxnl2 encoding RdCVFs, the loss of cones is more pronounced in the ventral retina. Conclusion The automated

Retinitispigmentosa is characterized by the sequential loss of rod and cone photoreceptors. The preservation of cones would prevent blindness due to their essential role in human vision. Rod-derived Cone Viability Factor is a thioredoxin-like protein that is secreted by rods and is involved in cone survival. To validate the activity of Rod-derived Cone Viability Factors (RdCVFs) as therapeutic agents for treating retinitisPigmentosa, we have developed e-conome, an automated cell counting platform for retinal flat mounts of rodent models of cone degeneration. This automated quantification method allows for faster data analysis thereby accelerating translational research. An inverted fluorescent microscope, motorized and coupled to a CCD camera records images of cones labeled with fluorescent peanut agglutinin lectin on flat-mounted retinas. In an average of 300 fields per retina, nine Z-planes at magnification X40 are acquired after two-stage autofocus individually for each field. The projection of the stack of 9 images is subject to a threshold, filtered to exclude aberrant images based on preset variables. The cones are identified by treating the resulting image using 13 variables empirically determined. The cone density is calculated over the 300 fields. The method was validated by comparison to the conventional stereological counting. The decrease in cone density in rd1 mouse was found to be equivalent to the decrease determined by stereological counting. We also studied the spatiotemporal pattern of the degeneration of cones in the rd1 mouse and show that while the reduction in cone density starts in the central part of the retina, cone degeneration progresses at the same speed over the whole retinal surface. We finally show that for mice with an inactivation of the Nucleoredoxin-like genes Nxnl1 or Nxnl2 encoding RdCVFs, the loss of cones is more pronounced in the ventral retina. The automated platform ℮-conome used here for retinal disease is a tool that

The Royal College of Surgeons (RCS) rat is a well-characterized model of autosomal recessive retinitispigmentosa (RP) due to a defect in the retinal pigment epithelium (RPE). It is homozygous for a null mutation in the gene encoding , a receptor tyrosine kinase found in RPE cells, that is required for phagocytosis of shed photoreceptor outer segments. The absence of Mertk results in accumulation of outer segment debris. This subsequently leads to progressive loss of photoreceptor cells. In order to evaluate the efficacy of lentiviral-mediated gene replacement therapy in the RCS rat, we produced recombinant VSV-G pseudotyped HIV-1-based lentiviruses containing a murine Mertk cDNA driven by a spleen focus forming virus (SFFV) promoter. The vector was subretinally injected into the right eye of 10-day-old RCS rats; the left eye was left untreated as an internal control. Here, we present a detailed assessment of the duration and extent of the morphological rescue and the resulting functional benefits. We examined animals at various time points over a period of 7 months by light and electron microscopy, and electroretinography. We observed correction of the phagocytic defect, slowing of photoreceptor cell loss and preservation of retinal function for up to 7 months. This study demonstrates the potential of gene therapy approaches for the treatment of retinal degenerations caused by defects specific to the RPE and supports the use of lentiviral vectors for the treatment of such disorders.

In the P23H rat model of retinitispigmentosa, the dopamine D2 receptor antagonists sulpiride and eticlopride appear to improve visual responses of retinal ganglion cells (RGCs) by increasing light sensitivity of RGCs and transforming abnormal, long-latency ON-center RGCs into OFF-center cells. Antipsychotic drugs are believed to mediate their therapeutic benefits by blocking D2 receptors. This investigation was conducted to test whether haloperidol (a typical antipsychotic drug) and clozapine (an atypical antipsychotic drug) could similarly alter the light responses of RGCs in the P23H rat retina. Extracellular recordings were made from RGCs in isolated P23H rat retinas. Responses of RGCs to flashes of light were evaluated before and during bath application of a drug. Both haloperidol and clozapine increased light sensitivity of RGCs on average by ∼0.3 log unit. For those ON-center RGCs that exhibit an abnormally long-latency response to the onset of a small spot of light, both haloperidol and clozapine brought out a short-latency OFF response and markedly reduced the long-latency ON response. The selective serotonin 5-HT2A antagonist MDL 100907 had similar effects on RGCs. The effects of haloperidol on light responses of RGCs can be explained by its D2 receptor antagonism. The effects of clozapine on light responses of RGCs on the other hand may largely be due to its 5-HT2A receptor antagonism. Overall, the results suggest that antipsychotic drugs may be useful in improving vision in patients with retinitispigmentosa.

Retinitispigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy.

Sectorial retinitispigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures.

Full Text Available Sectorial retinitispigmentosa (RP and optic disc pit (ODP are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures.

Background Retinitispigmentosa is a group of genetic disorders that involves the breakdown and loss of photoreceptors in the retina, resulting in progressive retinal degeneration and eventual blindness. The Argus II Retinal Prosthesis System is the only currently available surgical implantable device approved by Health Canada. It has been shown to improve visual function in patients with severe visual loss from advanced retinitispigmentosa. The objective of this analysis was to examine the clinical effectiveness, cost-effectiveness, budget impact, and safety of the Argus II system in improving visual function, as well as exploring patient experiences with the system. Methods We performed a systematic search of the literature for studies examining the effects of the Argus II retinal prosthesis system in patients with advanced retinitispigmentosa, and appraised the evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria, focusing on visual function, functional outcomes, quality of life, and adverse events. We developed a Markov decision-analytic model to assess the cost-effectiveness of the Argus II system compared with standard care over a 10-year time horizon. We also conducted a 5-year budget impact analysis. We used a qualitative design and an interview methodology to examine patients’ lived experience, and we used a modified grounded theory methodology to analyze information from interviews. Transcripts were coded, and themes were compared against one another. Results One multicentre international study and one single-centre study were included in the clinical review. In both studies, patients showed improved visual function with the Argus II system. However, the sight-threatening surgical complication rate was substantial. In the base-case analysis, the Argus II system was cost-effective compared with standard care only if willingness-to-pay was more than $207,616 per quality-adjusted life

To report a case of type 3 neovascular lesion in a patient with retinitispigmentosa (RP) complicated by macular edema. A 78-year-old man with a long follow-up for RP was referred for painless visual acuity decrease in the right eye. Best-corrected visual acuity was 20/125 in the right eye and 20/40 in the left. Fundus examination showed typical RP and macular edema in both eyes. In the right eye, spectral domain optical coherence tomography revealed a marked cystic macular edema associated with disruption of the Bruch membrane/retinal pigment epithelium complex overlying a pigmentary epithelium detachment, with a vascular structure which appeared to originate from the deep capillary plexus and to be connected with the subretinal pigment epithelium space. Optical coherence tomography angiography showed a high-flow vessel infiltrating the outer retinal layers in the deep capillary plexus segmentation, and a tuft-shaped, bright, high-flow network that seemed to be connected with the subretinal pigment epithelium space in the outer retinal layer segmentation. This presentation was consistent with an early type 3 neovascular lesion in the right eye. Type 3 neovascularization may be considered a possible complication of RP.

Full Text Available Purpose: To report a case of type 3 neovascular lesion in a patient with retinitispigmentosa (RP complicated by macular edema. Case Report: A 78-year-old man with a long follow-up for RP was referred for painless visual acuity decrease in the right eye. Best-corrected visual acuity was 20/125 in the right eye and 20/40 in the left. Fundus examination showed typical RP and macular edema in both eyes. In the right eye, spectral domain optical coherence tomography revealed a marked cystic macular edema associated with disruption of the Bruch membrane/retinal pigment epithelium complex overlying a pigmentary epithelium detachment, with a vascular structure which appeared to originate from the deep capillary plexus and to be connected with the subretinal pigment epithelium space. Optical coherence tomography angiography showed a high-flow vessel infiltrating the outer retinal layers in the deep capillary plexus segmentation, and a tuft-shaped, bright, high-flow network that seemed to be connected with the subretinal pigment epithelium space in the outer retinal layer segmentation. This presentation was consistent with an early type 3 neovascular lesion in the right eye. Conclusion: Type 3 neovascularization may be considered a possible complication of RP.

Retinitispigmentosa (RP) is a group of inherited disorders affecting 1 in 3000-7000 people and characterized by abnormalities of the photoreceptors (rods and cones) or the retinal pigment epithelium of the retina which lead to progressive visual loss. RP can be inherited in an autosomal dominant, autosomal recessive or X-linked manner. While usually limited to the eye, RP may also occur as part of a syndrome as in the Usher syndrome and Bardet-Biedl syndrome. Over 40 genes have been associated with RP so far, with the majority of them expressed in either the photoreceptors or the retinal pigment epithelium. The tremendous heterogeneity of the disease makes the genetics of RP complicated, thus rendering genotype-phenotype correlations not fully applicable yet. In addition to the multiplicity of mutations, in fact, different mutations in the same gene may cause different diseases. We will here review which genes are involved in the genesis of RP and how mutations can lead to retinal degeneration. In the future, a more thorough analysis of genetic and clinical data together with a better understanding of the genotype-phenotype correlation might allow to reveal important information with respect to the likelihood of disease development and choices of therapy.

Non syndromic forms of RetinitisPigmentosa (RP) constitute a collection of clinically and genetically heterogeneous inherited retinal degenerative diseases. They are characterized by a bilateral progressive visual loss susceptible to cause blindness. These diseases are transmitted through pedigrees according to all known modes of inheritance. They are bilateral and usually start during infancy. However, very early clinical presentations exist, such as those observed in children affected by Leber Congenital Amaurosis, as well as late onset autosomal dominant forms of retinitispigmentosa. The characteristic clinical aspect of the rod-cone RP dystrophies is marked by alterations of the peripheral retina associated with a night blindness and a progressive narrowing of the visual field. The ophthalmoscopic examination of RP patients commonly reveals thin retinal arteries and scattered pigmentary accumulations. In contrast, there are cone rod retinal dystrophies whose onset is marked by a decreased visual acuity before the appearance of any visual field alteration. Some forms of RPs display an ocular fundus devoid of any pigmentary alteration. Syndromic forms of RPs are not uncommon. The association of deafness with RP is detected in nearly 30% of the patients. Other associations with RP can include mental deficiency, facial dysmorphy, microcephaly, obesity, kidney deficiency, immune deficiencies, metabolic disorders. The existence of such syndromic forms of RP localizes RPs at the crossroad of several medical specialties. A long lasting collaboration between our department of ophthalmology and the department of medical genetics of the Necker-Sick Children Hospital has allowed us to establish numerous genotype-phenotype correlations, especially in LCA and Stargardt's disease. ABCR gene mutations cause Stargardt disease. ABCR mutations may also cause some types of Ages Related Macular Degenerations (AMD). Nowadays, there is no known efficient therapy available for

Describing the ophthalmic findings of an exudative vasculopathy called as Coats-like retinitispigmentosa on three patients. The etiology of the Coats-like retinitispigmentosa is obscure. The principal theories have been discussed in this article. Three observational case series have been discussed. Complete ophthalmic examinations and color fundus photos, visual field, and fluorescein angiography have been performed. We have identified 3 patients who have some typical clinical features of Coats-like retinitispigmentosa; peripheral serous retinal detachment, telangiectasia, prominent lipid deposition, pigmentary changes in peripheral retina, and loss of vision. None of the three patients had positive family history. All of the patients have had symptoms of nyctalopia, decreased central vision, and two of them have had constriction of visual field. All of the patients have had cataracts and two of them underwent cataract surgery. Fundus examination and fluorescein angiography of patients revealed typical retinitispigmentosa with Coats-type changes in bilateral inferiotemporal quadrants. A better understanding of clinical features and genetic etiology of Coats-type retinitispigmentosa will aid diagnosis and development of new therapies. If sufficient conditions arise, genetic factors that influence the expression of CRB1 mutations in Coats-like retinitispigmentosa should be detected.

Retinitispigmentosa is a group of genetically transmitted disorders affecting 1 in 3000-8000 individual people worldwide ultimately affecting the quality of life. Retinitispigmentosa is characterized as a heterogeneous genetic disorder which leads by progressive devolution of the retina leading to a progressive visual loss. It can occur in syndromic (with Usher syndrome and Bardet-Biedl syndrome) as well as non-syndromic nature. The mode of inheritance can be X-linked, autosomal dominant or autosomal recessive manner. To date 58 genes have been reported to associate with retinitispigmentosa most of them are either expressed in photoreceptors or the retinal pigment epithelium. This review focuses on the disease mechanisms and genetics of retinitispigmentosa. As retinitispigmentosa is tremendously heterogeneous disorder expressing a multiplicity of mutations; different variations in the same gene might induce different disorders. In recent years, latest technologies including whole-exome sequencing contributing effectively to uncover the hidden genesis of retinitispigmentosa by reporting new genetic mutations. In future, these advancements will help in better understanding the genotype-phenotype correlations of disease and likely to develop new therapies.

Full Text Available The data consists of sixty probands affected with Retinitispigmentosa. Syndromic cases were found in five percent of the RP probands. Segregation analysis was carried out on proband sibship data. The ascertainment probability was estimated at 0.5517. Analysis of the data by parental mating types of proband sibships indicated the presence of dominant forms of RP (2.05%. Analysis of proband sibships indicated the presence of low risk families in the Normal x Normal matings (45% and in the consanguineous matings (40%. The hypothesis of recessive inheritance could be confirmed only in multiplex sibships (p = 0.383 +/- 0.0793. Data on proband matings though incomplete conformed in general to autosomal recessive gene hypothesis.

Purpose: Describing the ophthalmic findings of an exudative vasculopathy called as Coats-like retinitispigmentosa on three patients. The etiology of the Coats-like retinitispigmentosa is obscure. The principal theories have been discussed in this article. Methods: Three observational case series have been discussed. Complete ophthalmic examinations and color fundus photos, visual field, and fluorescein angiography have been performed. Results: We have identified 3 patients who have some typ...

To present retinal pigmentary changes mimicking retinitispigmentosa (RP) as a finding of advanced uveitis. We retrospectively reviewed charts of patients without a family history of inherited retinal degenerations who presented with retinal pigment changes and signs of past or present intraocular inflammation. Comprehensive eye examination including best-corrected visual acuity, slit-lamp examination and dilated fundus examination was performed on all patients in addition to color fundus photography, optical coherence tomography, fluorescein angiography (FA), and full-field electroretinogram testing. We identified five patients with ages ranging from 33 to 66 years, who presented with RP-like retinal pigmentary changes which were eventually attributed to longstanding uveitis. The changes were bilateral in three cases and unilateral in two cases. Four of five cases presented with active inflammation, and the remaining case showed evidence of active intraocular inflammation during follow-up. This study highlights the overlapping features of advanced uveitis and RP including the extensive pigmentary changes. Careful review of possible past uveitis history, detailed examination of signs of past or present inflammation and ancillary testing, with FA often being most helpful, are required for the correct diagnosis. This is important, because intervention can prevent further damage if the cause of the pigmentary changes is destructive inflammation.

To assess the clinical and molecular genetic studies of patients with autosomal recessive retinitispigmentosa associated with a mutation in the arrestin gene. Results of molecular genetic screening and case reports with DNA analysis and clinical features. University medical center. One hundred twenty anamnestically unrelated patients with autosomal recessive retinitispigmentosa. DNA analysis was performed by single strand conformation polymorphism followed by nucleotide sequencing to search for a mutation in exon 11 of the arrestin gene. Clinical features were characterized by visual acuity slitlamp biomicroscopy, fundus examinations, fluorescein angiography, kinetic visual field testing, and electroretinography. We identified 3 unrelated patients with retinitispigmentosa associated with a homozygous 1-base-pair deletion mutation in codon 309 of the arrestin gene designated as 1147delA. All 3 patients showed pigmentary retinal degeneration in the midperipheral area with or without macular involvement. Patient 1 had a sibling with Oguchi disease associated with the same mutation. Patient 2 demonstrated pigmentary retinal degeneration associated with a golden-yellow reflex in the peripheral fundus. Patients 1 and 3 showed features of retinitispigmentosa without the golden-yellow fundus reflex. Although the arrestin 1147delA has been known as a frequent cause of Oguchi disease, this mutation also may be related to the pathogenesis of autosomal recessive retinitispigmentosa. This phenomenon may provide evidence of variable expressivity of the mutation in the arrestin gene.

Full Text Available Background. Dopamine (DA has a specific role in modulation of retinal function, renewal and phagocytosis of shed discs by the retinal pigment epithelium. Animal model of RCS (Royal College of Surgeons rats which have impaired retinal phagocytosis has shown an appearance similar to the clinical picture seen in patients with advanced retinitispigmentosa (RP. Based on RCS rats’ studies and the fact that DA has an important role in retinal renewal we assume that certain DA receptor polymorphisms might play a role in pathogenesis of RP.Materials and methods. We compared a group of 65 RP patients and 80 healthy individuals. Using PCR method and restriction with DdeI, TaqI or MspI restriction enzymes (DRD1, DRD2, DRD3 respectively we determined the polymorphisms of DRD1, DRD2 and DRD3. Three models of expression (codominant, dominant, recessive were statistically compared with χ 2-test.Results. We found an evidence for association between DRD2 TaqI RFLP, OR = 1.9 (95% CI: 1.7–2.3, p = 0.08, under autosome recessive model of inheritance. Other models for any of the DRD polymorphisms did not show a significant association with RP.Conclusions. A potential association was found between RP and DRD2 polymorphism. Further investigation is needed to confirm potential implication of DRD2 in the pathogenesis of RP.

Background The purpose of this study was to determine visual acuity at different contrast levels under photopic and mesopic conditions in patients with retinitispigmentosa. Methods Sixty eyes of 31 normal controls, 92 eyes of 52 patients with retinitispigmentosa without other ocular disorders (RP-1 group), and 20 eyes of 14 patients with retinitispigmentosa with cataracts and without other ocular disorders (RP-2 group) were studied. Conventional visual acuity was measured using a conventional Landolt ring chart with 100% contrast and luminance of 150 cd/m2. All of the patients with retinitispigmentosa had a decimal visual acuity better than 1.0. Contrast visual acuity was measured with the same Landolt ring chart with contrasts of 100% and 10% and under photopic (200 cd/m2) and mesopic (10 cd/m2) conditions. Decimal visual acuities were converted to logMAR units for the analyses. Results The 100% contrast visual acuity and the 10% contrast visual acuity determined under both photopic and mesopic conditions were significantly poorer in both the RP-1 and RP-2 groups than in the controls. The differences between the conventional visual acuity and the 100% contrast visual acuity were significantly greater in the RP-1 and RP-2 groups than in the controls under both photopic and mesopic conditions. The differences between the 100% contrast visual acuity and the 10% contrast visual acuity were not significant among the three groups under photopic and mesopic conditions. Conclusion Contrast visual acuities were greatly reduced in patients with retinitispigmentosa with relatively well preserved conventional visual acuity, and the contrast visual acuity was largely influenced by ambient light levels in patients with retinitispigmentosa. Although a longitudinal study for confirmation has to be performed, our findings indicate that contrast visual acuity is a better test to follow changes in visual function in patients with retinitispigmentosa. PMID:22069346

Purpose To analyze the retinal structure underlying the hyperautofluorescent ring visible on fundus autofluorescence in patients with retinitispigmentosa. Methods Twenty-four eyes of 13 patients with retinitispigmentosa, aged 13 years to 67 years, were studied. The integrity of the photoreceptor cilia, also known as the inner/outer segment junction of the photoreceptors, the outer nuclear layer, and retinal pigment epithelium, was evaluated outside, across, and inside the ring with spectral-domain optical coherence tomography (OCT). Results Inside the foveal area, fundus autofluorescence did not detect abnormalities. Outside the ring, fundus autofluorescence revealed hypoautofluorescence compatible with the photoreceptor/retinal pigment epithelium degeneration. Spectral-domain OCT inside the ring, in the area of normal foveal fundus autofluorescence, revealed an intact retinal structure in all eyes and total retinal thickness values that were within normal limits. Across the ring, inner/outer segment junction disruption was observed and the outer nuclear layer was decreased in thickness in a centrifugal direction in all eyes. Outside the hyperautofluorescent ring, the inner/outer segment junction and the outer nuclear layer appeared to be absent and there were signs of retinal pigment epithelium degeneration. Conclusion Disruption of the inner/outer segment junction and a decrease in outer retinal thickness were found across the central hyperautofluorescent ring seen in retinitispigmentosa. Outer segment phagocytosis by retinal pigment epithelium is necessary for the formation of an hyperautofluorescent ring. PMID:19584660

RetinitisPigmentosa (RP) is a retinal degenerative disease causing progressive blindness. Most research on RP is biomedical, and mostly from an observer perspective, therefore poorly reflecting the lived experience of having RP. Accordingly, the researcher conducted a retrospective qualitative self-study, to analyze reflections on his own…

A 75-year-old woman presented to her ophthalmologist complaining of visual loss for several years. The ophthalmic examination was remarkable for a bitemporal visual field defect. Magnetic resonance imaging (MRI) scan of the brain was normal without evidence of chiasm compression. Neuro-ophthalmic examination was consistent with a retinal rather than a chiasmal disease. Retinal multimodal imaging helped in the correct diagnosis of retinitispigmentosa, later confirmed by genetic testing.

Background Retinitispigmentosa is a group of inherited disorders characterized by the degeneration of the photoreceptors in the retina, resulting in progressive vision loss. The Argus II system is designed to restore partial functional vision in patients with profound vision loss from advanced retinitispigmentosa. At present, it is the only treatment option approved by Health Canada for this patient population. In June 2016, Health Quality Ontario published a health technology assessment of the Argus II retinal prosthesis system for patients with advanced retinitispigmentosa. Based on that assessment, the Ontario Health Technology Advisory Committee recommended against publicly funding the Argus II system for this population. It also recommended that Health Quality Ontario re-evaluate the evidence in 1 year. The objective of this report was to examine new evidence published since the 2016 health technology assessment. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences related to the Argus II system. We performed a systematic literature search for studies published since the 2016 Argus II health technology assessment. We developed a Markov decision-analytic model to assess the cost-effectiveness of the Argus II system compared with standard care, and we calculated incremental cost-effectiveness ratios over a 20-year time horizon. We also conducted a five-year budget impact analysis. Finally, we interviewed people with retinitispigmentosa about their lived experience with vision loss, and with the Argus II system. Results Four publications from one multicentre international study were included in the clinical review. Patients showed significant improvements in visual function and functional outcomes with the Argus II system, and these outcomes were sustained up to a 5-year follow-up (moderate quality of evidence). The safety profile was generally acceptable. In

To accelerate the development of new therapies, an inherited retinal degeneration model in a nonhuman primate would be useful to confirm the efficacy in preclinical studies. In this study, we describe the discovery of retinitispigmentosa in a cynomolgus monkey (Macaca fascicularis) pedigree. First, screening with fundus photography was performed on 1443 monkeys at the Tsukuba Primate Research Center. Ophthalmic examinations, such as indirect ophthalmoscopy, ERGs using RETeval, and optic coherent tomography (OCT) measurement, were then performed to confirm diagnosis. Retinal degeneration with cystoid macular edema was observed in both eyes of one 14-year-old female monkey. In her examinations, the full-field ERGs were nonrecordable and the outer layer of the retina in the parafoveal area was not visible on OCT imaging. Moreover, less frequent pigmentary retinal anomalies also were observed in her 3-year-old nephew. His full-field ERGs were almost nonrecordable and the outer layer was not visible in the peripheral retina. His father was her cousin (the son of her mother's older brother) and his mother was her younger half-sibling sister with a different father. The hereditary nature is highly probable (autosomal recessive inheritance suspected). However, whole-exome analysis performed identified no pathogenic mutations in these monkeys.

Full Text Available Retinal photoreceptors die during retinal synaptogenesis in a portion of retinal degeneration. Whether cone bipolar cells establish regular retinal mosaics and mature morphologies, and resist degeneration are not completely understood. To explore these issues, we backcrossed a transgenic mouse expressing enhanced green fluorescent protein (EGFP in one subset of cone bipolar cells (type 7 into rd1 mice, a classic mouse model of retinal degeneration, to examine the development and survival of cone bipolar cells in a background of retinal degeneration. Our data revealed that both the development and degeneration of cone bipolar cells are independent of the normal activity of cone photoreceptors. We found that type 7 cone bipolar cells achieved a uniform tiling of the retinal surface and developed normal dendritic and axonal arbors without the influence of cone photoreceptor innervation. On the other hand, degeneration of type 7 cone bipolar cells, contrary to our belief of central-to-peripheral progression, was spatially uniform across the retina independent of the spatiotemporal pattern of cone degeneration. The results have important implications for the design of more effective therapies to restore vision in retinal degeneration.

To determine whether normal function and structure, as recently found in forms of Usher syndrome, also occur in a population of patients with nonsyndromic retinitispigmentosa (RP). Patients with simplex, multiplex, or autosomal recessive RP (n = 238; ages 9-82 years) were studied with static chromatic perimetry. A subset was evaluated with optical coherence tomography (OCT). Co-localized visual sensitivity and photoreceptor nuclear layer thickness were measured across the central retina to establish the relationship of function and structure. Comparisons were made to patients with Usher syndrome (n = 83, ages 10-69 years). Cross-sectional psychophysical data identified patients with RP who had normal rod- and cone-mediated function in the central retina. There were two other patterns with greater dysfunction, and longitudinal data confirmed that progression can occur from normal rod and cone function to cone-only central islands. The retinal extent of normal laminar architecture by OCT corresponded to the extent of normal visual function in patients with RP. Central retinal preservation of normal function and structure did not show a relationship with age or retained peripheral function. Usher syndrome results were like those in nonsyndromic RP. Regional disease variation is a well-known finding in RP. Unexpected was the observation that patients with presumed recessive RP can have regions with functionally and structurally normal retina. Such patients will require special consideration in future clinical trials of either focal or systemic treatment. Whether there is a common molecular mechanism shared by forms of RP with normal regions of retina warrants further study.

Retinitispigmentosa is a term commonly given to a group of inherited and progressive disorders which affect the photoreceptors of the retina. As part of an ongoing research programme throughout Spain, clinical, epidemiological, and genetic studies have been carried out on these diseases. Here, we report the relative frequencies of the different genetic types in 503 non-syndromic and 89 syndromic RP families of Spanish origin. The most frequent syndromic RP forms were Usher syndrome type 1 (20/89 families = 30%) and Usher syndrome type 2 (44 families = 49%). Among non-syndromic RP forms, 12% were autosomal dominant, 39% autosomal recessive and 4% X-linked. Forty-one percent were isolated or simplex cases and in 4% the genetic type could not be established.

Retinitispigmentosa (RP) is a heterogeneous group of inherited retinal disorders. Diagnosis can be challenging as more than 40 genes are known to cause non-syndromic RP and phenotypic expression can differ significantly resulting in variations in disease severity, age of onset, rate of progression, and clinical findings. We describe the clinical manifestations of RP, the more commonly known causative gene mutations, and the genotypic-phenotypic correlation of RP. PMID:22131872

Statistical analysis of 10 personal (client) variables and four program variables related to 76 people who became blind from retinitispigmentosa revealed that 6 variables predicted clients' rehabilitation outcomes: age, gender, race, work status, amount of case-service money spent on the client's behalf, and number of changes in career objectives…

Recent evidence suggesting the involvement of mutant rhodopsin proteins in the pathogenesis of autosomal recessive retinitispigmentosa has prompted us to investigate whether this form of the disease shows non-allelic genetic heterogeneity, as has previously been shown to be the case in autosomal

Discusses the workplace-based accommodations that allowed a 45-year-old Southeast Asian woman with a moderate hearing deficit, who was diagnosed with retinitispigmentosa, to continue to perform her duties as a checkout operator. Emphasizes the importance of conducting workplace evaluations before providers offer advice on vocational matters. (CR)

The study found that apartheid impacted the sociopsychological and physical circumstances of 12 African and 11 White people with retinitispigmentosa in South Africa. Findings are discussed in terms of onset of condition, effects on subjects' lives, knowledge of social services, and needs unmet by existing services. (JDD)

This article reviews the consequences of RetinitisPigmentosa, a retinal degenerative disease with progressive reduction of the visual field, visual acuity, contrast sensitivity, and night blindness. RetinitisPigmentosa is addressed from both a psychological and an educational standpoint, focusing on the impact on learning, emotional well-being,…

The Royal College of Surgeons (RCS) rat is an established animal model of retinitispigmentosa, a family of inherited retinal diseases which starts with loss of peripheral vision and progresses to eventual blindness. Blood flow (BF), an important physiological parameter, is intricately coupled to metabolic function under normal physiological conditions and is perturbed in many neurological and retinal diseases. This study reports non-invasive high-resolution MRI (44 × 44 × 600 μm) to image quantitative retinal and choroidal BF and layer-specific retinal thicknesses in RCS rat retinas at different stages of retinal degeneration compared with age-matched controls. The unique ability to separate retinal and choroidal BF was made possible by the depth-resolved MRI technique. RBF decreased with progressive retinal degeneration, but ChBF did not change in RCS rats up to post-natal day 90. We concluded that choroidal and retinal circulations have different susceptibility to progressive retinal degeneration in RCS rats. Layer-specific retinal thickness became progressively thinner and was corroborated by histological analysis in the same animals. MRI can detect progressive anatomical and BF changes during retinal degeneration with laminar resolution. PMID:22721720

Full Text Available Summary: Retinitispigmentosa (RP is an irreversible, inherited retinopathy in which early-onset nyctalopia is observed. Despite the genetic heterogeneity of RP, RPGR mutations are the most common causes of this disease. Here, we generated induced pluripotent stem cells (iPSCs from three RP patients with different frameshift mutations in the RPGR gene, which were then differentiated into retinal pigment epithelium (RPE cells and well-structured retinal organoids possessing electrophysiological properties. We observed significant defects in photoreceptor in terms of morphology, localization, transcriptional profiling, and electrophysiological activity. Furthermore, shorted cilium was found in patient iPSCs, RPE cells, and three-dimensional retinal organoids. CRISPR-Cas9-mediated correction of RPGR mutation rescued photoreceptor structure and electrophysiological property, reversed the observed ciliopathy, and restored gene expression to a level in accordance with that in the control using transcriptome-based analysis. This study recapitulated the pathogenesis of RPGR using patient-specific organoids and achieved targeted gene therapy of RPGR mutations in a dish as proof-of-concept evidence. : Jin and colleagues demonstrate that patient-specific iPSC-derived 3D retinae can recapitulate disease progress of retinitispigmentosa through presenting defects in photoreceptor morphology, gene profile, and electrophysiology, as well as the defective ciliogenesis in iPSCs, iPSC-RPE, and 3D retinae. CRISPR/Cas9-mediated gene correction can rescue not only photoreceptor structure and electrophysiological property but also observed ciliopathy. Keywords: RPGR, photoreceptor, electrophysiology, retinitispigmentosa, patient-derived iPSCs, retinal organoid, RPE cells, cilium, ciliopathy, disease modeling

Analysis of the clinical course of retinal degeneration in 40 patients in whom one suspected a retinal dystrophy "sine pigmento", a sector or unilateral dystrophy or a mixed conerod form. Eventually the diagnosis was possible only after performing a complex of investigations: the visual acuity, visual field, adaptation, the ERG and in some cases also the fluorescein angiography. No exact correlation between the results of a particular test could be established but the degree of abnormality of some of them was decisive for the moment of the first reference of the patient for examination by an ophthalmic specialist. In the course of observation the progress of the condition was evident but the dynamics of it was not the same and it was dependent on many factors.

Retinitispigmentosa (RP) has a prevalence of approximately one in 4000; 25%–30% of these cases are autosomal dominant retinitispigmentosa (adRP). Like other forms of inherited retinal disease, adRP is exceptionally heterogeneous. Mutations in more than 25 genes are known to cause adRP, more than 1000 mutations have been reported in these genes, clinical findings are highly variable, and there is considerable overlap with other types of inherited disease. Currently, it is possible to detect disease-causing mutations in 50%–75% of adRP families in select populations. Genetic diagnosis of adRP has advantages over other forms of RP because segregation of disease in families is a useful tool for identifying and confirming potentially pathogenic variants, but there are disadvantages too. In addition to identifying the cause of disease in the remaining 25% of adRP families, a central challenge is reconciling clinical diagnosis, family history, and molecular findings in patients and families. PMID:25304133

Purpose To quantify the prevalence and effect on visual acuity of macular cysts in a large cohort of patients with retinitispigmentosa. Methods In 316 patients with typical forms of retinitispigmentosa, we measured visual acuities with Early Treatment Diabetic Retinopathy Study (ETDRS) charts, detected macular cysts with optical coherence tomography (OCT), and quantified retinal thicknesses by OCT. We used the FREQ, LOGISTIC, and GENMOD procedures of SAS to evaluate possible risk factors for cyst prevalence and the MIXED procedure to quantify the relationships of visual acuity to retinal thickness measured at different locations within the macula. Results We found macular cysts in 28% of the patients, 40% of whom had cysts in only one eye. Macular cysts were seen most often in patients with dominant disease and not at all in patients with X-linked disease (p = 0.006). In eyes with macular cysts, multiple regression analysis revealed that visual acuity was inversely and independently related to retinal thickness at the foveal center (p = 0.038) and within a ring spanning an eccentricity of 5° to 10° from the foveal center (p = 0.004). Conclusions Macular cysts are a common occurrence in retinitispigmentosa, especially among patients with dominantly-inherited disease. Visual acuity is influenced by edema in the parafovea, as well as in the fovea. PMID:18552390

Full Text Available Mutations in the EYS (eyes shut homolog gene are a common cause of autosomal recessive (ar retinitispigmentosa (RP. Without a mammalian model of human EYS disease, there is limited understanding of details of disease expression and rates of progression of the retinal degeneration. We studied clinically and with chromatic static perimetry, spectral-domain optical coherence tomography (OCT, and en face autofluoresence imaging, a cohort of 15 patients (ages 12–51 at first visit, some of whom had longitudinal data of function and structure. Rod sensitivity was able to be measured by chromatic perimetry in most patients at their earliest visits and some patients retained patchy rod function into the fifth decade of life. As expected from RP, cone sensitivity persisted after rod function was no longer measurable. The photoreceptor nuclear layer of the central retina was abnormal except at the fovea in most patients at first visit. Perifoveal disease measured over a period of years indicated that photoreceptor structural loss was followed by dysmorphology of the inner retina and loss of retinal pigment epithelial integrity. Although there could be variability in severity, preliminary analyses of the rates of vision loss suggested that EYS is a more rapidly progressive disease than other ciliopathies causing arRP, such as USH2A and MAK.

Full Text Available Congenital hepatic fibrosis is a rare cause of portal hypertension and esophageal varices in children. We report cases of siblings with biopsy proven congenital hepatic fibrosis and with atypical retinitispigmentosa. They presented with repeated episodes of jaundice along with progressive decrease of vision in night. They had hepatosplenomegaly and portal hypertension with esophageal varices. One of the siblings had a large regenerating nodule replacing the entire right lobe of the liver and other one developed repeated hematemesis. This constellation of diagnosis belongs to the ciliopathy group of disorders. The spectrum of ciliopathy disorders has been evolving, and it varies from mild to severe manifestations.

Full Text Available Retinitispigmentosa is a degenerative retinal disease characterized by progressive photoreceptor damage, which causes loss of peripheral and night vision and the development of tunnel vision and may result in loss of central vision. This study describes a patient with retinitispigmentosa caused by a mutation in the ABCA4 gene with complex allele c.1622T>C, p.L541P; c.3113C>T, p.A1038V in homozygous state.

Full Text Available Purpose: To evaluate the effect of acupuncture therapy on visual function of patients with retinitis-pigmentosa (RP. Methods: In a prospective study, 23 RP subjects received ten sessions of body-acupuncture. Pre and post-treatment evaluations included best corrected visual acuity (BCVA, uncorrected visual acuity (UCVA, near visual acuity (NVA, and static 30-2 perimetry. Results: UCVA, BCVA, and NVA improvements after acupuncture therapy were statistically and clinically significant (P = 0.048, P = 0.0005, P = 0.002, respectively. The changes of mean foveal threshold (MFT and mean deviation (MD were statistically significant (P = 0.031, P = 0.02. There were no statistically significant difference between different age group and genders. Subjective symptoms of improvement were seen in most of cases. Conclusion: Future studies are needed to show the effect of acupuncture therapy on visual function of patients with RP. Keywords: Retina, Retinitispigmentosa, Acupuncture, Chinese medicine

Background The purpose of this study was to observe the characteristic findings of spectral-domain optical coherence tomography (SD-OCT) images in the retinas of patients with retinitispigmentosa and to evaluate their distribution patterns in the early and advanced stages of the disease. Methods A total of 184 patients (368 eyes) with retinitispigmentosa were observed using SD-OCT. We studied the presence or absence of continuous inner/outer segment (IS/OS) lines, presence of thinning of the retinal pigment epithelium-Bruch’s membrane complex, and distribution patterns of hyperreflective foci in the inner and outer nuclear layers (INL and ONL). Results The IS/OS junction had partially disappeared in 275 eyes, which were at the early stage of retinitispigmentosa (group X), whereas the junction had totally disappeared in 93, which were at the advanced stage of retinitispigmentosa (group Y). Hyperreflective foci in the INL were observed in a significantly larger proportion of the eyes in group X than in group Y (90% versus 61%, Pretinitis pigmentosa and hyperreflective foci in the ONL were more frequently observed in the advanced stage. Hyperreflective foci may be indicative of changes in the retinal structure at each stage of retinitispigmentosa. PMID:24591813

Since 1985, at least nine studies of the average rate of cone loss in retinitispigmentosa (RP) populations have yielded conflicting average rate constant values (-k), differing by 90-160%. This is surprising, since, except for the first two investigations, the Harvard or Johns Hopkins' protocols used in these studies were identical with respect to: use of the same exponential decline model, calculation of average -k from individual patient k values, monitoring patients over similarly large time frames, and excluding data exhibiting floor and ceiling effects. A detailed analysis of Harvard's and Hopkins' protocols and data revealed two subtle differences: (i) Hopkins' use of half-life t0.5 (or t(1/e)) for expressing patient cone-loss rates rather than k as used by Harvard; (ii) Harvard obtaining substantially more +k from improving fields due to dormant-cone recovery effects and "small -k" values than Hopkins' ("small -k" is defined as less than -0.040 year(-1)), e.g., 16% +k, 31% small -k, vs. Hopkins' 3% and 6% respectively. Since t0.5=0.693/k, it follows that when k=0, or is very small, t0.5 (or t(1/e)) is respectively infinity or a very large number. This unfortunate mathematical property (which also prevents t0.5 (t(1/e)) histogram construction corresponding to -k to +k) caused Hopkins' to delete all "small -k" and all +k due to "strong leverage". Naturally this contributed to Hopkins' larger average -k. Difference (ii) led us to re-evaluate the Harvard/Hopkins' exponential unchanging -k model. In its place we propose a model of increasing biochemical stresses from dying rods on cones during RP progression: increasing oxidative stresses and trophic factor deficiencies (e.g., RdCVF), and RPE malfunction. Our kinetic analysis showed rod loss to follow exponential kinetics with unchanging -k due to constant genetic stresses, thereby providing a theoretical basis for Clarke et al.'s empirical observation of such kinetics with eleven animal models of RP. In

RetinitisPigmentosa (RP) is the most common form of inherited retinal dystrophy (IRD) characterized ultimately by photoreceptors degeneration. Exhibiting great clinical and genetic heterogeneity, RP can be inherited as an autosomal dominant (ad), autosomal recessive (ar) and X-linked (xl) disorder. Although the relative prevalence of each form varies somewhat between populations, a major proportion (41% in Spain) of patients represent simplex cases (sRP) in which the mode of inheritance is unknown. Molecular genetic diagnostic is crucial, but also challenging, for sRP patients because any of the 81 RP genes identified to date may be causative. Herein, we report the use of a customized targeted gene panel consisting of 68 IRD genes for the molecular characterization of 106 sRP cases. The diagnostic rate was 62.26% (66 of 106) with a proportion of clinical refinements of 30.3%, demonstrating the high efficiency of this genomic approach even for clinically ambiguous cases. The high number of patients diagnosed here has allowed us to study in detail the genetic basis of the sRP. The solved sRP cohort is composed of 62.1% of arRP cases, 24.2% of adRP and 13.6% of xlRP, which implies consequences for counselling of patients and families. PMID:28157192

Retinitispigmentosa (RP) is a blinding disease often associated with mutations in rhodopsin, a light-sensing G protein-coupled receptor and phospholipid scramblase. Most RP-associated mutations affect rhodopsin's activity or transport to disc membranes. Intriguingly, some mutations produce apparently normal rhodopsins that nevertheless cause disease. Here we show that three such enigmatic mutations--F45L, V209M and F220C--yield fully functional visual pigments that bind the 11-cis retinal chromophore, activate the G protein transducin, traffic to the light-sensitive photoreceptor compartment and scramble phospholipids. However, tests of scramblase activity show that unlike wild-type rhodopsin that functionally reconstitutes into liposomes as dimers or multimers, F45L, V209M and F220C rhodopsins behave as monomers. This result was confirmed in pull-down experiments. Our data suggest that the photoreceptor pathology associated with expression of these enigmatic RP-associated pigments arises from their unexpected inability to dimerize via transmembrane helices 1 and 5.

Purpose To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitispigmentosa. Methods Observational case series. Patients diagnosed with late-onset retinitispigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed. Results All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitispigmentosa through electroretinogram testing. Conclusion Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitispigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis. PMID:23899229

Over 100 point mutations in the rhodopsin gene have been associated with retinitispigmentosa (RP), a family of inherited visual disorders. Among these, we focused on characterizing the S186W mutation. We compared the thermal properties of the S186W mutant with another RP-causing mutant, D190N, and with WT rhodopsin. To assess thermal stability, we measured the rate of two thermal reactions contributing to the thermal decay of rhodopsin as follows: thermal isomerization of 11-cis-retinal and hydrolysis of the protonated Schiff base linkage between the 11-cis-retinal chromophore and opsin protein. We used UV-visible spectroscopy and HPLC to examine the kinetics of these reactions at 37 and 55 °C for WT and mutant rhodopsin purified from HEK293 cells. Compared with WT rhodopsin and the D190N mutant, the S186W mutation dramatically increases the rates of both thermal isomerization and dark state hydrolysis of the Schiff base by 1–2 orders of magnitude. The results suggest that the S186W mutant thermally destabilizes rhodopsin by disrupting a hydrogen bond network at the receptor's active site. The decrease in the thermal stability of dark state rhodopsin is likely to be associated with higher levels of dark noise that undermine the sensitivity of rhodopsin, potentially accounting for night blindness in the early stages of RP. Further studies of the thermal stability of additional pathogenic rhodopsin mutations in conjunction with clinical studies are expected to provide insight into the molecular mechanism of RP and test the correlation between rhodopsin's thermal stability and RP progression in patients. PMID:23625926

In humans, the Crumbs homolog-1 (CRB1) gene is mutated in autosomal recessive Leber congenital amaurosis and early-onset retinitispigmentosa. In mammals, the Crumbs family is composed of: CRB1, CRB2, CRB3A and CRB3B. Recently, we showed that removal of mouse Crb2 from retinal progenitor cells, and

Full Text Available Aims : To determine waveforms of multifocal electroretinogram (mfERG in patients with retinitispigmentosa (RP contributing significantly to the overall retinal response by using principal components′ analysis. Settings and Design: Prospective, non-randomized, single-visit, observational, case-control study from a single tertiary ophthalmic center. Materials and Methods: Patients with various forms of RP underwent mfERG testing for a period of one year. The first-order kernel responses of RP cases were compared with concurrently recruited healthy controls. Statistical Analysis Used: Parametric data was analyzed using the unpaired t test for differences between the implicit time and amplitudes of cases and controls. Principal components′ analysis was done for each implicit time and amplitude in cases with RP using the Varimax rotation method. Results: From March 2006 to March 2007, 24 cases with typical RP (56%, 47 eyes were included in the final analysis. Their mean age was 33.7 years (19-69 ± 15.5 years. Comparison of latencies and amplitudes among RP cases with log MAR acuity ≤ 0.18 and those > 0.18, revealed significant difference in the implicit time (P1 in Ring 2 only (P=0.028. Two components (predominently from Ring 1 and 2 each contributing 66.8% and 88.8% of the total variance in the data for latencies and amplitudes respectively, were seen. Conclusions : The first two rings of the mfERG contributed to the variance of waveforms in RP, irrespective of the visual acuity and poor visual field results.

Full Text Available Purpose: To compare electroretinogram (ERG characteristics in patients with retinitispigmentosa (RP and normal subjects using frequency domain analysis. Methods: Five basic ERG recordings were performed in normal subjects and patients with a clinical diagnosis of RP according to the ISCEV (International Society of Clinical Electrophysiology of Vision protocol. Frequency domain analysis was performed by MATLAB software. Different frequency domain parameters were compared between the study groups. Results: Peak frequency (Fmod of flicker and oscillatory responses in RP patients showed significant (P<0.0001 high pass response as compared to normal controls. Peak frequency (Fmod of the other responses was not significantly different between the two groups. Conclusion: In addition to conventional ERG using time domain methods, frequency domain analysis may be useful for diagnosis of RP. Oscillatory and flicker responses may be analyzed in frequency domain. Fast Fourier transform may reveal two distinct high pass responses (shift to higher frequencies in Fmod. Time and frequency domain analyses may be performed simultaneously with many modern ERG machines and may therefore be recommended in RP patients.

To determine the role of rhodopsin (RHO) gene mutations in patients with sector retinitispigmentosa (RP) from Northern Ireland. A case series of sector RP in a tertiary ocular genetics clinic. Four patients with sector RP were recruited from the Royal Victoria Hospital (Belfast, Northern Ireland) and Altnagelvin Hospital (Londonderry, Northern Ireland) following informed consent. The diagnosis of sector RP was based on clinical examination, International Society for Clinical Electrophysiology of Vision (ISCEV) standard electrophysiology, and visual field analysis. DNA was extracted from peripheral blood leucocytes and the coding regions and adjacent flanking intronic sequences of the RHO gene were polymerase chain reaction (PCR) amplified and cycle sequenced. Rhodopsin mutational status. A heterozygous missense mutation in RHO (c.173C > T) resulting in a non-conservative substitution of threonine to methionine (p. Thr58Met) was identified in one patient and was absent from 360 control individuals. This non-conservative substitution (p.Thr58Met) replaces a highly evolutionary conserved polar hydrophilic threonine residue with a non-polar hydrophobic methionine residue at position 58 near the cytoplasmic border of helix A of RHO. The study identified a RHO gene mutation (p.Thr58Met) not previously reported in RP in a patient with sector RP. These findings outline the phenotypic variability associated with RHO mutations. It has been proposed that the regional effects of RHO mutations are likely to result from interplay between mutant alleles and other genetic, epigenetic and environmental factors.

The fatty acid composition and the glutathione-peroxidase activity (GSH-Px) of erythrocytes and platelets, the production of malondialdehyde (MDA) by platelets and the activity of the main systems of transmembrane cation transport in erythrocyte have been studied in 12 patients (5 males and 7 females) affected by retinitispigmentosa (RP). A remarkable increase of saturated fatty acids (SFA), particularly of stearic acid (C18:0), has been noted in these patients. The reduced unsaturated/saturated fatty acids ratio (PUFA/SFA) observed in both erythrocytes and platelets and the decrease of arachidonic acid in platelets may depend by an active peroxidation process as documented by the increase of MDA. Platelet glutathione-peroxidase (PTL-GSH-PX) and plasma retinol were in the normal range, whereas erythrocyte glutathione-peroxidase (E-GSH-PX), MDA and plasma alfa-toco-pherol were increased in patients with RP. The activities of Na(+)-K+ pump, cotransport and Na(+)-Li+ countertransport were normal in RP erythrocytes.

The authors searched for point mutations in every exon of the rhodopsin gene in 150 patients from separate families with autosomal dominant retinitispigmentosa. Including the 4 mutations the authors reported previously, they found a total of 17 different mutations that correlate with the disease. Each of these mutations is a single-base substitution corresponding to a single amino acid substitution. Based on current models for the structure of rhodopsin, 3 of the 17 mutant amino acids are normally located on the cytoplasmic side of the protein, 6 in transmembrane domains, and 8 on the intradiscal side. Forty-three of the 150 patients (29%) carry 1 of these mutations, and no patient has more than 1 mutation. In every family with a mutation so far analyzed, the mutation cosegregates with the disease. They found one instance of a mutation in an affected patient that was absent in both unaffected parents (i.e., a new germ-line mutation), indicating that some isolate cases of retinitispigmentosa carry a mutation of the rhodopsin gene

Inherited retinal dystrophies, such as retinitispigmentosa (RP), include a group of relatively rare hereditary diseases caused by mutations in genes that code for proteins involved in the maintenance and function of the photoreceptor cells (cones and rods). The different forms of RP consist of progressive neurodegenerative disorders which are generally related to various and severe limitations of visual performances. In the course of typical RP (rod-cone dystrophy), the affected individuals first experience night-blindness and/or visual field constriction (secondary to rod dysfunctions), followed by variable alterations of the central vision (due to cone damages). On the other hand, during the atypical form of RP (cone-rod dystrophy), the cone’s functionalities are prevalently disrupted in comparison with the rod’s ones. The basic diagnosis of RP relies upon the documentation of unremitting loss in photoreceptor activity by electroretinogram and/or visual field testing. The prevalence of all RP typologies is variably reported in about one case for each 3000-5000 individuals, with a total of about two millions of affected persons worldwide. The inherited retinal dystrophies are sometimes the epiphenomenon of a complex framework (syndromic RP), but more often they represent an isolated disorder (about 85-90 % of cases). Although 200 causative RP mutations have been hitherto detected in more than 100 different genes, the molecular defect is identifiable in just about the 50% of the analyzed patients with RP. Not only the RP genotypes are very heterogeneous, but also the patients with the same mutation can be affected by different phenotypic manifestations. RP can be inherited as autosomal dominant, autosomal recessive or X-linked trait, and many sporadic forms are diagnosed in patients with no affected relatives. Dissecting the clinico-genetic complexity of RP has become an attainable objective by means of large-scale research projects, in which the collaboration

Retinal stem cells (RSCs) have been demonstrated at the proliferating marginal regions from the pars plana of ciliary body to the ciliary marginal zone (CMZ) in adult lower vertebrates and mammals. Investigations in the lower vertebrates have provided some evidence that RSCs can proliferate following retinal damage; however, the evidence that this occurs in mammals is not clear. In this study, we explored RSCs proliferation potential of adult mammalian in proliferating marginal regions of Royal College of Surgeons (RCS) rats, an animal model for retinitispigmentosa (RP). The proliferation was evaluated using BrdU labeling, and Chx-10 as markers to discern progenitor cell of CMZ in Long-Evan's and RCS rats at different postnatal day (PND) after eye opening. We found that few Chx-10 and BrdU labeled cells in the proliferating marginal regions of Long-Evan's rats, which significantly increased in RCS rats at PND30 and PND60. Consistent with this, Chx-10/Vimentin double staining cells in the center retina of RCS rats increased significantly at PND30 after eye opening. In addition, mRNA expression of Shh, Ptch1 and Smo was up-regulated in RCS rats at PND60 compared to age-matched Long-Evan's rats, which revealed Shh/ptc pathway involving in the activation of RSCs. These results suggest that RSCs in the mammalian retinal proliferating marginal regions has the potential to regenerate following degeneration.

Full Text Available Naoki Tojo, Tomoko Nakamura, Chiharu Fuchizawa, Toshihiko Oiwake, Atsushi HayashiDepartment of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, JapanBackground: The purpose of this study was to examine cone photoreceptors in the macula of patients with retinitispigmentosa using an adaptive optics fundus camera and to investigate any correlations between cone photoreceptor density and findings on optical coherence tomography and fundus autofluorescence.Methods: We examined two patients with typical retinitispigmentosa who underwent ophthalmological examination, including measurement of visual acuity, and gathering of electroretinographic, optical coherence tomographic, fundus autofluorescent, and adaptive optics fundus images. The cone photoreceptors in the adaptive optics images of the two patients with retinitispigmentosa and five healthy subjects were analyzed.Results: An abnormal parafoveal ring of high-density fundus autofluorescence was observed in the macula in both patients. The border of the ring corresponded to the border of the external limiting membrane and the inner segment and outer segment line in the optical coherence tomographic images. Cone photoreceptors at the abnormal parafoveal ring were blurred and decreased in the adaptive optics images. The blurred area corresponded to the abnormal parafoveal ring in the fundus autofluorescence images. Cone densities were low at the blurred areas and at the nasal and temporal retina along a line from the fovea compared with those of healthy controls. The results for cone spacing and Voronoi domains in the macula corresponded with those for the cone densities.Conclusion: Cone densities were heavily decreased in the macula, especially at the parafoveal ring on high-density fundus autofluorescence in both patients with retinitispigmentosa. Adaptive optics images enabled us to observe in vivo changes in the cone photoreceptors of

Purpose To determine the spectrum and frequency of rhodopsin gene (RHO) mutations in Korean patients with retinitispigmentosa (RP) and to characterize genotype–phenotype correlations in patients with mutations. Methods The RHO mutations were screened by direct sequencing, and mutation prevalence was measured in patients and controls. The impact of missense mutations to RP was predicted by segregation analysis, peptide sequence alignment, and in silico analysis. The severity of disease in patients with the missense mutations was compared by visual acuity, electroretinography, optical coherence tomography, and kinetic visual field testing. Results Five heterozygous mutations were identified in six of 302 probands with RP, including a novel mutation (c.893C>A, p.A298D) and four known mutations (c.50C>T, p.T17M; c.533A>G, p.Y178C; c.888G>T, p.K296N; and c.1040C>T, p.P347L). The allele frequency of missense mutations was measured in 114 ethnically matched controls. p.A298D, newly identified in a sporadic patient, had never been found in controls and was predicted to be pathogenic. Among the patients with the missense mutations, we observed the most severe phenotype in patients with p.P347L, less severe phenotypes in patients with p.Y178C or p.A298D, and a relatively moderate phenotype in a patient with p.T17M. Conclusions The results reveal the spectrum of RHO mutations in Korean RP patients and clinical features that vary according to mutations. Our findings will be useful for understanding these genetic spectra and the genotype–phenotype correlations and will therefore help with predicting disease prognosis and facilitating the development of gene therapy. PMID:21677794

Full Text Available Introduction: To describe clinical and electrophysiological features of a patient with unilateral RetinitisPigmentosa (RP. Case: A 29-year-old female with a long history of progressive visual disturbance in the right eye has undergone multiple eye examinations during the past eight years. There was nothing noticeable in her past medical and ocular history. Comprehensive eye examinations were done in the first visit. All data was suggestive of right eye RP. Posterior segment fundal examination findings were: a pallor waxy disc, vessel attenuation, and extended pigmentary degeneration of the mid-peripheral retina. The left eye examination was normal. Comparing the automated 60 degree and 30 degree visual fields of both eyes obviously showed significant defects in the right eye visual field but normal in the left eye. All of the probable infectious agents, which can cause similar ocular manifestations, were ruled out by serological tests. The standard photopic and scotopic electroretinographies were significantly reduced in amplitude in the right eye; however, they were normal in the left eye. Also, the standard Electro-Oculography (EOG results were the same as the Electro-Retinography (ERG ones in both eyes. Eye examinations were normal in other family members. Over an eight-year follow-up period, progressive deteriorating vision has gradually become more noticeable in the right eye. The left eye has been completely normal since. This data was compatible with the Francois and Verriesr unilateral RP diagnostic criteria. Conclusion: Clinical signs and symptoms, a minimum of a five-year follow-up period, and confirmatory ERG and EOG are very helpful to diagnose andaffirm the case of unilateral RP.

A 14-year-old girl complained of a sudden decrease in right visual acuity. The patient had night blindness, a mottled retina but no pigments, extinguished scotopic electroretinographic response, central scotoma in the right eye and rhegmatogenous retinal detachment. She had initially received laser photocoagulation around the retinal tear and then corticosteroid therapy, cryoretinopexy and segmental buckling. Her right visual acuity increased to 1.0. The association of retinitispigmentosa sine pigmento, retrobulbar optic neuritis and rhegmatogenous retinal detachment, as demonstrated in our patient, may be uncommon. Copyright 2000 S. Karger AG, Basel

To report a heterozygous female presenting with an early-onset and severe form of X-linked retinitispigmentosa (XLRP). This is a case series presenting the clinical findings in a heterozygous female with XLRP and two of her family members. Fundus photography, fundus autofluorescence, ocular coherence tomography, and visual perimetry are presented. The proband reported here is a heterozygous female who presented at the age of 8 years with an early onset and aggressive form of XLRP. The patient belongs to a four-generation family with a total of three affected females and four affected males. The patient was initially diagnosed with retinitispigmentosa (RP) at the age of 4 years. Genetic testing identified a heterozygous donor splice site mutation in intron 1 (IVS1 + 1G > A) of the retinitispigmentosa GTPase regulator gene. The father of the proband was diagnosed with RP when he was a young child. The sister of the proband, evaluated at the age of 6 years, showed macular pigmentary changes. Although carriers of XLRP are usually asymptomatic or have a mild disease of late onset, the proband presented here exhibited an early-onset, aggressive form of the disease. It is not clear why some carrier females manifest a severe phenotype. A better understanding of the genetic processes involved in the penetrance and expressivity of XLRP in heterozygous females could assist in providing the appropriate counseling to affected families.

Retinitispigmentosa (RP) is a degenerative disease of the retina that causes the severe impairment of visual functioning similar to low vision, leading, in many cases, to blindness. Because the construct of self-concept plays a key role in personality, this study was designed to measure self-concept in a group of young adults with RP. The…

It is often assumed that persons who develop ocular disease have some form of visual experience that makes them aware of their deficits. However, in the case of peripheral field loss or decreasing vision in dim lighting, as in retinitispigmentosa, for example, symptoms are more obscure and may not be as easily identified by the persons who have…

Linkage analysis and homogeneity tests were carried out in 15 Dutch families segregating X-linked retinitispigmentosa (X L R P). The study included segregation data for eight polymorphic DNA markers from the short arm of the human X chromosome. The results of both multipoint linkage analysis in

Full Text Available Purpose: To report the efficacy of intravitreal dexamethasone implant in a patient with retinitispigmentosa and bilateral cystoid macular edema unresponsive to topical carbonic anhydrase inhibitors. Case Report: A 36-year-old man with bilateral cystoid macular edema associated with retinitispigmentosa that was unresponsive to topical carbonic anhydrase inhibitors underwent bilateral 0.7-mg intravitreal dexamethasone implants two weeks apart. Spectral domain optical coherence tomography revealed resolution of macular edema one week following each injection in both eyes and his visual acuity improved. However, macular edema recurred two months later in OS and three months later in OD. Second implant was considered for both eyes. No implant-related complication was experienced during the follow-up of seven months. Conclusion: Inflammatory process seems to play a role in retinitispigmentosa. Intravitreal dexamethasone implant may offer retina specialists a therapeutic option especially in cases unresponsive to other treatment regimens in eyes with retinitispigmentosa-related macular edema.

A retrospective study was performed of patients with retinitispigmentosa (RP) registered at the Department of Ophthalmogenetics of the Netherlands Ophthalmic Research Institute. The aim was to establish the relative frequencies of the genetic modes and to attempt a clinical subclassification. Of

Retinitispigmentosa (RP) causes restriction of the visual field, progressive vision loss, and night blindness. This article presents an overview of the most common problems in orientation and mobility (O&M) for individuals with RP, appropriate interventions, vision science discoveries related to RP, and the impact of RP on functional visual…

OBJECTIVE: To determine the refractive error in patients with autosomal recessive retinitispigmentosa (arRP) caused by RP1 mutations and to compare it with that of other genetic subtypes of RP. METHODS: Twenty-six individuals had arRP with RP1 mutations, 25 had autosomal dominant RP (adRP) with RP1

PURPOSE: Retinitispigmentosa (RP) is a genetically heterogeneous disorder characterized by progressive loss of vision. The aim of this study was to identify the causative mutations in 272 Spanish families using a genotyping microarray. METHODS: 272 unrelated Spanish families, 107 with autosomal

Retinitispigmentosa was diagnosed in 101 persons from 53 families. The prognosis for visual function was most favourable for the autosomal dominant group (38 patients from 8 families). The autosomal recessive group (40 patients from 25 families) and the 19 solitary cases were very heterogeneous, with prognosis ranging from favourable to very bad. There was a higher intrafamiliar correlation in the autosomal recessive than in the autosomal dominant group. In 28 patients from 18 families with Usher syndrome, almost all had good visual function until 30 years of age, and few had useful visual function after the age of 50. The age when the patients were registered varied between the different genetic types of retinitispigmentosa, reflecting differences in prognosis. Therefore, ascertainment probability and prevalence were calculated for each genetic group separately. The prevalence of retinitispigmentosa in Norway, all genetic groups included, was calculated to be 1/4440, the autosomal dominant type of the disease being the most frequent. The prevalence of Usher syndrome was calculated to be 3.6/100,000. Both retinitispigmentosa and Usher syndrome were more prevalent in Laps.

To analyze the structure and visual function of regions bordering the hyperautofluorescent ring/arcs in retinitispigmentosa. Twenty-one retinitispigmentosa patients (21 eyes) with rings/arcs and 21 normal individuals (21 eyes) were studied. Visual sensitivity in the central 10° was measured with microperimetry. Retinal structure was evaluated with spectral-domain optical coherence tomography. The distance from the fovea to disruption/loss of the inner outer segment (IS/OS) junction and thicknesses of the total receptor plus retinal pigment epithelial complex and outer segment plus retinal pigment epithelial complex layers were measured. Results were compared with measurements of the distance from the fovea to the inner and outer borders of the ring/arc seen on fundus autofluorescence. Disruption/loss of the inner outer segment junction occurred closer to the inner border of the ring/arc and it was closer to the fovea in eight eyes. For 19 eyes, outer segment plus and receptor plus RPE complex thicknesses were significantly decreased at locations closer to the fovea than the appearance of the inner border of hyperautofluorescence. Mean visual sensitivity was decreased inside, across, and outside the ring/arc by 3.5 ± 3.8, 8.9 ± 4.8, and 17.0 ± 2.4 dB, respectively. Structural and functional changes can occur inside the hyperfluorescent ring/arc in retinitispigmentosa.

The purpose of this study was to examine cone photoreceptors in the macula of patients with retinitispigmentosa using an adaptive optics fundus camera and to investigate any correlations between cone photoreceptor density and findings on optical coherence tomography and fundus autofluorescence. We examined two patients with typical retinitispigmentosa who underwent ophthalmological examination, including measurement of visual acuity, and gathering of electroretinographic, optical coherence tomographic, fundus autofluorescent, and adaptive optics fundus images. The cone photoreceptors in the adaptive optics images of the two patients with retinitispigmentosa and five healthy subjects were analyzed. An abnormal parafoveal ring of high-density fundus autofluorescence was observed in the macula in both patients. The border of the ring corresponded to the border of the external limiting membrane and the inner segment and outer segment line in the optical coherence tomographic images. Cone photoreceptors at the abnormal parafoveal ring were blurred and decreased in the adaptive optics images. The blurred area corresponded to the abnormal parafoveal ring in the fundus autofluorescence images. Cone densities were low at the blurred areas and at the nasal and temporal retina along a line from the fovea compared with those of healthy controls. The results for cone spacing and Voronoi domains in the macula corresponded with those for the cone densities. Cone densities were heavily decreased in the macula, especially at the parafoveal ring on high-density fundus autofluorescence in both patients with retinitispigmentosa. Adaptive optics images enabled us to observe in vivo changes in the cone photoreceptors of patients with retinitispigmentosa, which corresponded to changes in the optical coherence tomographic and fundus autofluorescence images.

Full Text Available The aim of this study was to gain information about disease prevalence and to identify the responsible genes for inherited retinal dystrophies (IRD in Japanese populations. Clinical and molecular evaluations were performed on 349 patients with IRD. For segregation analyses, 63 of their family members were employed. Bioinformatics data from 1,208 Japanese individuals were used as controls. Molecular diagnosis was obtained by direct sequencing in a stepwise fashion utilizing one or two panels of 15 and 27 genes for retinitispigmentosa patients. If a specific clinical diagnosis was suspected, direct sequencing of disease-specific genes, that is, ABCA4 for Stargardt disease, was conducted. Limited availability of intrafamily information and decreasing family size hampered identifying inherited patterns. Differential disease profiles with lower prevalence of Stargardt disease from European and North American populations were obtained. We found 205 sequence variants in 159 of 349 probands with an identification rate of 45.6%. This study found 43 novel sequence variants. In silico analysis suggests that 20 of 25 novel missense variants are pathogenic. EYS mutations had the highest prevalence at 23.5%. c.4957_4958insA and c.8868C>A were the two major EYS mutations identified in this cohort. EYS mutations are the most prevalent among Japanese patients with IRD.

The aim of this study was to gain information about disease prevalence and to identify the responsible genes for inherited retinal dystrophies (IRD) in Japanese populations. Clinical and molecular evaluations were performed on 349 patients with IRD. For segregation analyses, 63 of their family members were employed. Bioinformatics data from 1,208 Japanese individuals were used as controls. Molecular diagnosis was obtained by direct sequencing in a stepwise fashion utilizing one or two panels of 15 and 27 genes for retinitispigmentosa patients. If a specific clinical diagnosis was suspected, direct sequencing of disease-specific genes, that is, ABCA4 for Stargardt disease, was conducted. Limited availability of intrafamily information and decreasing family size hampered identifying inherited patterns. Differential disease profiles with lower prevalence of Stargardt disease from European and North American populations were obtained. We found 205 sequence variants in 159 of 349 probands with an identification rate of 45.6%. This study found 43 novel sequence variants. In silico analysis suggests that 20 of 25 novel missense variants are pathogenic. EYS mutations had the highest prevalence at 23.5%. c.4957_4958insA and c.8868C>A were the two major EYS mutations identified in this cohort. EYS mutations are the most prevalent among Japanese patients with IRD.

RetinitisPigmentosa is a common form of hereditary retinal degeneration constituting the largest Mendelian genetic cause of blindness in the developed world. It has been widely suggested that oxidative stress possibly contributes to its pathogenesis. We measured the levels of total antioxidant capacity, free nitrotyrosine, thiobarbituric acid reactive substances (TBARS) formation, extracellular superoxide dismutase (SOD3) activity, protein, metabolites of the nitric oxide/cyclic GMP pathway, heme oxygenase-I and inducible nitric oxide synthase expression in aqueous humor or/and peripheral blood from fifty-six patients with retinitispigmentosa and sixty subjects without systemic or ocular oxidative stress-related disease. Multivariate analysis of covariance revealed that retinitispigmentosa alters ocular antioxidant defence machinery and the redox status in blood. Patients with retinitispigmentosa present low total antioxidant capacity including reduced SOD3 activity and protein concentration in aqueous humor. Patients also show reduced SOD3 activity, increased TBARS formation and upregulation of the nitric oxide/cyclic GMP pathway in peripheral blood. Together these findings confirmed the hypothesis that patients with retinitispigmentosa present reduced ocular antioxidant status. Moreover, these patients show changes in some oxidative-nitrosative markers in the peripheral blood. Further studies are needed to clarify the relationship between these peripheral markers and retinitispigmentosa. PMID:24069283

To estimate the mean rates of ocular function loss in patients with autosomal recessive retinitispigmentosa due to USH2A mutations. In 125 patients with USH2A mutations, longitudinal regression was used to estimate mean rates of change in Snellen visual acuity, Goldmann visual field area (V4e white test light), and 30-Hz (cone) full-field electroretinogram amplitude. These rates were compared with those of previously studied cohorts with dominant retinitispigmentosa due to RHO mutations and with X-linked retinitispigmentosa due to RPGR mutations. Rates of change in patients with the Cys759Phe mutation, the USH2A mutation associated with nonsyndromic disease, were compared with rates of change in patients with the Glu767fs mutation, the most common USH2A mutation associated with Usher syndrome type II (i.e., retinitispigmentosa and hearing loss). Mean annual exponential rates of decline for the USH2A patients were 2.6% for visual acuity, 7.0% for visual field area, and 13.2% for electroretinogram amplitude. The rate of acuity loss fell between the corresponding rates for the RHO and RPGR patients, whereas the rates for field and ERG amplitude loss were faster than those for the RHO and RPGR patients. No significant differences were found for patients with the Cys759Phe mutation versus patients with the Glu767fs mutation. On average, USH2A patients lose visual acuity faster than RHO patients and slower than RPGR patients. USH2A patients lose visual field and cone electroretinogram amplitude faster than patients with RHO or RPGR mutations. Patients with a nonsyndromic USH2A mutation have the same retinal disease course as patients with syndromic USH2A disease.

To describe a case of hypertension and retinitispigmentosa presenting with a unilateral macular star. Case report. A 17-year-old female with chronic kidney disease and hypertension presented with a mild blurring of vision in the left eye. There was a history of night blindness. Both eyes had optic disc pallor, arteriolar attenuation, and peripheral bony spicules suggestive of the triad of retinitispigmentosa. Macular star was seen in the left eye alone. We ascribe the macular star to hypertension as the patient had only a mild decrease in vision, no relative afferent pupillary defect, and similar visual evoked response amplitude and latency in both eyes. Unilateral macular star may be seen in hypertension and may simulate neuroretinitis in the clinical setting.

Full Text Available André Omgbwa Eballe1, Godefroy Koki2, Claude Bernard Emche2, Lucienne Assumpta Bella2, Jeanne Mayouego Kouam2, Justin Melong31Faculty of Medicine and Pharmaceutical Sciences, University of Douala; 2Faculty of Medicine and Biomedical Sciences, University of Yaoundé; 3Translation Unit, Ministry of Public Health, Yaoundé, CameroonAim: We performed a retrospective, analytical study in February 2010 on all retinitispigmentosa cases seen during ophthalmologic consultation at the Gyneco-Obstetrics and Pediatric Hospital of Yaounde between March 2002 and December 2009 (82 months. The aim of this research was to determine the significance of blindness and visual impairment associated with retinitispigmentosa in Cameroon.Results: Forty cases were reported, corresponding to a hospital prevalence of 1.6/1000 (21 men and 19 women. The average age of the patients was 43.3 ± 18 years, ranging between 6 and 74 years. Bilateral blindness and low vision was noted in 30% and 27.5% of patients, respectively. The average age of patients with low vision was 40.38 ± 16.27 years and the average age of those with bilateral blindness was 51.08 ± 15.79 years. Retinitispigmentosa was bilateral in all cases and isolated (without any eye or general additional disease in 67.5% of cases.Conclusion: Visual impairment is common and becomes even more severe with aging. Patients should be screened to enable them to benefit from management focusing on both appropriate treatment and genetic counseling.Keywords: retinitispigmentosa, Cameroon, blindness, Yaoundé

The electron microscopic structure of cilia from the inferior turbinate of the nose was studied in 12 adults, four with chronic sinusitis, one with allergic rhinitis, two with bronchiectasis, three with deviated nasal septum, and two normals. The changes are compared with those found in nasal cilia in 14 patients with retinitispigmentosa. There were compound cilia in the seven cases with chronic sinusitis, allergic rhinitis, and bronchiectasis but, apart from this, the structure of the cilia...

Purpose The aim of the present work was to identify and characterize large rearrangements involving the USH2A gene in patients with Usher syndrome and nonsyndromic retinitispigmentosa. Methods The multiplex ligation-dependent probe amplification (MLPA) technique combined with a customized array-based comparative genomic hybridization (aCGH) analysis was applied to 40 unrelated patients previously screened for point mutations in the USH2A gene in which none or only one pathologic mutation was...

The electron microscopic structure of cilia from the inferior turbinate of the nose was studied in 12 adults, four with chronic sinusitis, one with allergic rhinitis, two with bronchiectasis, three with deviated nasal septum, and two normals. The changes are compared with those found in nasal cilia in 14 patients with retinitispigmentosa. There were compound cilia in the seven cases with chronic sinusitis, allergic rhinitis, and bronchiectasis but, apart from this, the structure of the cilia was similar in all 12 cases. There were variations in the microtubular pattern in about 4% of cilia, dynein arms were not seen in 4%, and in the rest an average of 5-6 dynein arms were seen in each cilium. The orientation of the cilia was 0 to 90 degrees. In the retinitispigmentosa patients there was a highly significant increase in cilial abnormalities. The establishment on a quantitative basis of the variations in normal structure of nasal cilila facilitated the recognition of an association between cilial abnormalities and retinitispigmentosa and should help in the identification of associations that may exist between cilial abnormalities and other diseases. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 7 Fig. 8 PMID:7400333

Three brothers, one 10-year-old and a pair of 14-year-old dizygotic twins--expressed the classical, early-onset retinitispigmentosa (RP) with typical ophthalmoscopic findings, night blindness, visual field constricted to 10 degrees and flat ERG response. All three brothers were also diagnosed with primary ciliary dyskinesia (PCD) and had recurrent respiratory infections, chronic sinusitis and bronchiectasis. In all of them, resection of the middle lobe of the right lung was performed. A similar clinical picture of coexisting RP and PCD was noted in the brother of the probands' mother. All probands displayed situs solitus. Consistent with the X-linked mode of RP inheritance, there were also three obligatory female carriers of the disorder in this family: the mother of the affected boys, her mother and a daughter of her brother. In all of them, retinitispigmentosa "sine pigmento" was found with milder but clinically significant symptoms (mild night blindness, visual field constricted to 30 degrees, and scotopic and photopic ERG responses reduced to 30-60%). No extraocular symptoms were detected in any of the heterozygous female carriers. This family presents an example of two rare phenomena: X-linked dominant retinitispigmentosa (with milder expression in females) and a rare combination of RP with recurrent respiratory infections due to PCD.

Full Text Available AIM: To study the genes responsible for retinitispigmentosa. METHODS: A total of 15 Chinese families with retinitispigmentosa, containing 94 sporadically afflicted cases, were recruited. The targeted sequences were captured using the Target_Eye_365_V3 chip and sequenced using the BGISEQ-500 sequencer, according to the manufacturer’s instructions. Data were aligned to UCSC Genome Browser build hg19, using the Burroughs Wheeler Aligner MEM algorithm. Local realignment was performed with the Genome Analysis Toolkit (GATK v.3.3.0 IndelRealigner, and variants were called with the Genome Analysis Toolkit Haplotypecaller, without any use of imputation. Variants were filtered against a panel derived from 1000 Genomes Project, 1000G_ASN, ESP6500, ExAC and dbSNP138. In all members of Family ONE and Family TWO with available DNA samples, the genetic variant was validated using Sanger sequencing. RESULTS: A novel, pathogenic variant of retinitispigmentosa, c.357_358delAA (p.Ser119SerfsX5 was identified in PRPF31 in 2 of 15 autosomal-dominant retinitispigmentosa (ADRP families, as well as in one, sporadic case. Sanger sequencing was performed upon probands, as well as upon other family members. This novel, pathogenic genotype co-segregated with retinitispigmentosa phenotype in these two families. CONCLUSION: ADRP is a subtype of retinitispigmentosa, defined by its genotype, which accounts for 20%-40% of the retinitispigmentosa patients. Our study thus expands the spectrum of PRPF31 mutations known to occur in ADRP, and provides further demonstration of the applicability of the BGISEQ500 sequencer for genomics research.

AIM To study the genes responsible for retinitispigmentosa. METHODS A total of 15 Chinese families with retinitispigmentosa, containing 94 sporadically afflicted cases, were recruited. The targeted sequences were captured using the Target_Eye_365_V3 chip and sequenced using the BGISEQ-500 sequencer, according to the manufacturer's instructions. Data were aligned to UCSC Genome Browser build hg19, using the Burroughs Wheeler Aligner MEM algorithm. Local realignment was performed with the Genome Analysis Toolkit (GATK v.3.3.0) IndelRealigner, and variants were called with the Genome Analysis Toolkit Haplotypecaller, without any use of imputation. Variants were filtered against a panel derived from 1000 Genomes Project, 1000G_ASN, ESP6500, ExAC and dbSNP138. In all members of Family ONE and Family TWO with available DNA samples, the genetic variant was validated using Sanger sequencing. RESULTS A novel, pathogenic variant of retinitispigmentosa, c.357_358delAA (p.Ser119SerfsX5) was identified in PRPF31 in 2 of 15 autosomal-dominant retinitispigmentosa (ADRP) families, as well as in one, sporadic case. Sanger sequencing was performed upon probands, as well as upon other family members. This novel, pathogenic genotype co-segregated with retinitispigmentosa phenotype in these two families. CONCLUSION ADRP is a subtype of retinitispigmentosa, defined by its genotype, which accounts for 20%-40% of the retinitispigmentosa patients. Our study thus expands the spectrum of PRPF31 mutations known to occur in ADRP, and provides further demonstration of the applicability of the BGISEQ500 sequencer for genomics research. PMID:29375987

To correlate the structure of the macula, as measured by spectral-domain optical coherence tomography (SD-OCT) and function, as measured by microperimetry (MAIA) in patients with retinitispigmentosa (RP) and relatively good visual acuity. Prospective, cross-sectional, non-intervention study. Patients with RP. Thirty patients with RP and good central visual acuity were identified. Each patient underwent SD-OCT of the macula and microperimetry. The images were overlaid using the custom-designed software. The retinal sensitivity by microperimetry was correlated with corresponding retinal thickness, as measured by the SD-OCT. ELM, COST, and IS/OS junction were scored as intact, disrupted, or absent. Comparing the retinal sensitivity on the MAIA with various measurements on the SD-OCT. The retinal sensitivity on the MAIA showed a significant correlation with total retinal thickness and outer retinal thickness on the SD-OCT. There was no association with either the inner retinal thickness or the choroidal thickness. ORT showed a statistically significant correlation with the anatomical classification of ELM (r=-0.76, Pmacula in patients with RP. These studies are important to establish surrogate markers that can be used as end points for various tests in future therapeutic clinical trials.

Full Text Available Hiroshi Ohguro1, Yukihiko Mashima2, Mitsuru Nakazawa31Department of Ophthalmology, Sapporo Medical University School of Medicine, 2Department of Ophthalmology, Keio University School of Medicine, 3Department of Ophthalmology, Hirosaki University School of Medicine, JapanPurpose: The aim of this study was to elucidate the role of endothelin-1 (ET-1 in the pathophysiology of retinitispigmentosa (RP.Methods: Plasma ET-1 levels and ophthalmic features in 50 RP patients were compared with those in 20 healthy-eye control subjects. Plasma ET-1 concentrations were determined using a commercially available enzyme-linked immunosorbent assay kit.Results: Mean plasma ET-1 levels of RP patients (1.88 ± 0.56 pg/mL were significantly lower than those of control subjects (2.30 ± 0.30 pg/mL, Mann-Whitney’s U test; P < 0.01. However, ET-1 concentrations varied markedly in each patient. Among RP patients, a significant correlation of ET-1 concentrations was not observed in terms of its hereditary forms or other clinical factors.Conclusion: ET-1 may be important in the pathogenesis of RP, and measurement of its plasma concentrations may also contribute to additional insights into the retinal hemodynamics of RP.Keywords: endothelin-1, retinitispigmentosa, retinal hemodynamics

PURPOSE: To provide the first detailed clinical description in patients with RP caused by recessive mutations in IMPG2. METHODS: This international collaborative study includes 17 RP patients with inherited retinal disease caused by mutations in IMPG2. The patients were clinically (re-)examined,

Full Text Available Background. Retinitispigmentosa (RP comprises a group of inherited disorders in which patients typically lose night vision in adolescence and then lose peripheral vision in young adulthood before eventually losing central vision later in life. A retrospective case-control study was performed to evaluate differences in ocular biometric parameters in primary angle-closure glaucoma (PACG patients with and without concomitant RP to determine whether a relationship exists between PACG and RP. Methods. We used ultrasound biomicroscopy (UBM to measure anterior chamber depth (ACD. A-scan biometry was carried out to measure lens thickness (LT and axial length (AL. Propensity score matching and mixed linear regression model analysis were conducted. 23 patients with chronic primary angle-closure glaucoma (CPACG associated with RP, 21 patients with acute primary angle-closure glaucoma (APACG associated with RP, 270 patients with CPACG, and 269 patients with APACG were recruited for this study. Results. There were no significant differences on ACDs, ALs, and relative lens position (RLP (P>0.05 between patients with PACG associated with RP and patients with PACG; however, patients with APACG associated with RP had a significantly greater LT than patients with APACG (P<0.05. Conclusion. Patients with PACG associated with RP had the same biometric parameter characteristic as the patients with CPACG and APACG. This may suggest that RP is a coincidental relationship with angle-closure glaucoma.

The aim of the study was to elucidate the genetic background of retinitispigmentosa (RP) in a Faroe Islands population, a genetic isolate in the North Atlantic Ocean.......The aim of the study was to elucidate the genetic background of retinitispigmentosa (RP) in a Faroe Islands population, a genetic isolate in the North Atlantic Ocean....

OBJECTIVE: To identify mutations in the AIPL1, CRB1, GUCY2D, RPE65, and RPGRIP1 genes in patients with juvenile retinitispigmentosa. METHODS: Mutation analysis was carried out in a group of 35 unrelated patients with juvenile autosomal recessive retinitispigmentosa (ARRP), Leber's congenital

To determine the type of ABCR mutations that segregate in a family that manifests both Stargardt disease (STGD) and retinitispigmentosa (RP), and the functional consequences of the underlying mutations. Direct sequencing of all 50 exons and flanking intronic regions of ABCR was performed for the STGD- and RP-affected relatives. RNA hybridization, Western blot analysis, and azido-adenosine triphosphate (ATP) labeling was used to determine the effect of disease-associated ABCR mutations in an in vitro assay system. Compound heterozygous missense mutations were identified in patients with STGD and RP. STGD-affected individual AR682-03 was compound heterozygous for the mutation 2588G-->C and a complex allele, [W1408R; R1640W]. RP-affected individuals AR682-04 and-05 were compound heterozygous for the complex allele [W1408R; R1640W] and the missense mutation V767D. Functional analysis of the mutation V767D by Western blot and ATP binding revealed a severe reduction in protein expression. In vitro analysis of ABCR protein with the mutations W1408R and R1640W showed a moderate effect of these individual mutations on expression and ATP-binding; the complex allele [W1408R; R1640W] caused a severe reduction in protein expression. These data reveal that missense ABCR mutations may be associated with RP. Functional analysis reveals that the RP-associated missense ABCR mutations are likely to be functionally null. These studies of the complex allele W1408R; R1640W suggest a synergistic effect of the individual mutations. These data are congruent with a model in which RP is associated with homozygous null mutations and with the notion that severity of retinal disease is inversely related to residual ABCR activity.

PURPOSE: We investigated whether retinis pigmentosa (RP) patients with residual visual field of < 100 degrees could perceive heading from optic flow. METHODS: Four RP patients and four age-matched normally sighted control subjects viewed displays simulating an observer walking over a ground. In experiment 1, subjects viewed either the entire display with free fixation (full-field condition) or through an aperture with a fixation point at the center (aperture condition). In experiment 2, patients viewed displays of different durations. RESULTS: RP patients' performance was comparable to that of the age-matched control subjects: heading judgment was better in the full-field condition than in the aperture condition. Increasing display duration from 0.5 s to 1 s improved patients' heading performance, but giving them more time (3 s) to gather more visual information did not consistently further improve their performance. CONCLUSIONS: RP patients use active scanning eye movements to compensate for their visual field loss in heading perception; they might be able to gather sufficient optic flow information for heading perception in about 1 s.

Full Text Available Retinitispigmentosa (RP is a heterogeneous group of monogenic disorders characterized by progressive death of the light-sensing photoreceptor cells of the outer neural retina. We recently identified novel hypomorphic mutations in the tRNA Nucleotidyl Transferase, CCA-Adding 1 (TRNT1 gene that cause early-onset RP. To model this disease in vitro, we generated patient-specific iPSCs and iPSC-derived retinal organoids from dermal fibroblasts of patients with molecularly confirmed TRNT1-associated RP. Pluripotency was confirmed using rt-PCR, immunocytochemistry, and a TaqMan Scorecard Assay. Mutations in TRNT1 caused reduced levels of full-length TRNT1 protein and expression of a truncated smaller protein in both patient-specific iPSCs and iPSC-derived retinal organoids. Patient-specific iPSCs and iPSC-derived retinal organoids exhibited a deficit in autophagy, as evidenced by aberrant accumulation of LC3-II and elevated levels of oxidative stress. Autologous stem cell-based disease modeling will provide a platform for testing multiple avenues of treatment in patients suffering from TRNT1-associated RP.

Full Text Available Abstract Introduction Refsum disease is a potentially lethal and disabling condition associated with retinitispigmentosa in which early treatment can prevent some of the systemic manifestations. Case presentation We present the cases of two brothers with a diagnosis of retinitispigmentosa from childhood in whom Refsum disease was subsequently diagnosed midlife, after routine enquiry into hand and feet abnormalities. Subsequent treatment through dietary modification stabilised visual impairment and has prevented development of neurological complications to date. Conclusion It is therefore important to consider the diagnosis of Refsum disease in any patient with autosomal recessive or simplex retinitispigmentosa, and to enquire about the presence of "unusual" feet or hands in such patients.

Using multiple imaging modalities, we evaluated the changes in photoreceptor cells and retinal pigment epithelium (RPE) that are associated with bone spicule-shaped melanin pigmentation in retinitispigmentosa. In a cohort of 60 patients with retinitispigmentosa, short-wavelength autofluorescence, near-infrared autofluorescence (NIR-AF), NIR reflectance, spectral domain optical coherence tomography, and color fundus images were studied. Central AF rings were visible in both short-wavelength autofluorescence and NIR-AF images. Bone spicule pigmentation was nonreflective in NIR reflectance, hypoautofluorescent with short-wavelength autofluorescence and NIR-AF imaging, and presented as intraretinal hyperreflective foci in spectral domain optical coherence tomography images. In areas beyond the AF ring outer border, the photoreceptor ellipsoid zone band was absent in spectral domain optical coherence tomography and the visibility of choroidal vessels in short-wavelength autofluorescence, NIR-AF, and NIR reflectance images was indicative of reduced RPE pigmentation. Choroidal visibility was most pronounced in the zone approaching peripheral areas of bone spicule pigmentation; here RPE/Bruch membrane thinning became apparent in spectral domain optical coherence tomography. These findings are consistent with a process by which RPE cells vacate their monolayer and migrate into inner retina in response to photoreceptor cell degeneration. The remaining RPE spread undergo thinning and consequently become less pigmented. An explanation for the absence of NIR-AF melanin signal in relation to bone spicule pigmentation is not forthcoming.

To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitispigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

Microdeletions Glu767(1-bp del), Thr967(1-bp del), and Leu1446(2-bp del) in the human USH2A gene have been reported to cause Usher syndrome type II, a disorder characterized by retinitispigmentosa (RP) and mild-to-severe hearing loss. Each of these three frameshift mutations is predicted to lead to an unstable mRNA transcript that, if translated, would result in a truncated protein lacking the carboxy terminus. Here, we report Cys759Phe, a novel missense mutation in this gene that changes an...

Full Text Available Background. This study was conducted to assess whether pattern ERG is a sensitive test in evaluating the retinal function in patients with retinitispigmentosa. We wanted to determine how pattern ERG, reflecting the activity of inner retinal layers, is related to other psychophysical tests such as perimetry and visual acuity.Methods. An analysis was performed on 50 eyes of 25 patients with typical rod-cone retinitispigmentosa. The standard Snellen visual acuity was tested. Visual field sensitivity was measured with automated static perimetry (Octopus G2 program where mean defect was taken as an index of visual field loss. In kinetic perimetry (Goldmann the average radius of the visual field measured with target II/4 and V/4 was calculated. Transient pattern ERG and all five flash ERG responses were also measured according to ISCEV standards. Amplitudes of pattern ERG P50 and N95 waves were compared to results of visual acuity and visual field testing.Results. In our group of 25 RP patients with visual acuity ranging from 0.16 to 1.0, PERG responses were preserved much better than full field ERGs. 72% of them had still recordable PERG responses, while 48% had cone and only 32% maximal responses. Scotopic rod responses were extinguished in all eyes. The normalized amplitudes of the PERG responses were also much higher (43.5% than cone (22.5% or maximal responses (4.5%. A strong correlation of both P50 and N95 amplitudes with Octopus mean defect index was found. In kinetic perimetry the correlation with PERG amplitudes was also high, but it was better with II/4 than with V/4 target. Patients with high preserved ERG responses had good visual acuity. In all patients with visual acuity less than 0.4 both flash and pattern ERG responses were already absent.Conclusions. This study shows that pattern ERG is an objective and sensitive test in evaluating the functional visual loss in retinitispigmentosa. Amplitudes of P50 and N95 responses are linearly

To analyse the mode of inheritance and clinical characteristics of retinitispigmentosa (RP) patients with consanguineous marriage. RP patients were recruited for this study in Ningxia Eye Hospital from September 2009 to July 2011. All patients received complete ophthalmic examination. The mode of inheritance were determined based on family history and marriage history. Clinical features were characterized by complete ophthalmic examinations including visual acuity, macular OCT, visual field and electroretinogram (ERG). A total of 143 individuals with RP (33 families) were recruited. Based on analysis of family history and marriage history, 20 RP families (23 patients) had consanguineous marriage history accounted for 60.6% RP families (16.1% RP patients). There were 4 patients (from 4 families) diagnosed as Usher syndrome. In 20 RP families with consanguineous marriage history, 7 families (35.0%) were Hui ethnicity and 13 families (65%) were Han ethnicity. The marriages of 15 families were between first cousins and 3 families were between second cousins, only 2 families were between half cousins matrimony. Of 23 RP patients, 12 were males and 11 were females. The average age of onset was 11.4 ± 6.8 years and the average age of recruitment was (32.0 ± 13.5) years. The best-corrected visual acuity was less than 0.6 in 78.2% patients. According to the features of the fundus, 13 patients were classical retinitispigmentosa and 10 patients were retinitispigmentosa sine pigmento. Visual field examination showed that all patients had varying degrees of peripheral visual field defect. Retinal neuroepithelial layer of macular and peripheral retina became thinner and retinal photoreceptors were disappeared. The average thickness of macular fovea was (186.1 ± 78.7) µm on right eyes and (187.4 ± 76.3) µm on left eyes. The incidence of RP with consanguineous marriages was high in Ningxia Region. The mode of inheritance of RP patients with consanguinity is autosomal

Retinitispigmentosa is the name given to a heterogeneous group of hereditary retinal degenerations characterized by progressive visual field loss, pigmentary changes of the retina, abnormal electroretinograms, and, frequently, night blindness. In this study, we investigated a family with dominant cone-rod degeneration, a variant form of retinitispigmentosa. We used microsatellite markers to test for linkage to the disease locus and excluded all mapped autosomal loci. However, a marker from ...

Full Text Available Mikiko Takezawa, Soichi Tetsuka, Akihiro KakehashiDepartment of Ophthalmology, Jichi Medical University, Saitama Medical Center, Saitama, Saitama, JapanAbstract: We report the possible mechanism of development of cystoid macular edema (CME in retinitispigmentosa (RP in the case of a 68-year-old woman with RP and CME in the right eye and resolving CME in the left eye. Spectral domain optical coherence tomography showed CME and posterior vitreoschisis in the nasal quadrant of the fundus without a posterior vitreous detachment (PVD. This vitreous pathology suggested bilateral thickening and shrinkage of the posterior vitreous cortex. In the right eye, CME was evident with no vitreofoveal separation. However, in the left eye, minimal change was seen in the CME associated with a focal shallow PVD over the fovea. The best-corrected visual acuity (BCVA in the left eye increased to 0.3 from 0.15 7 years after the first visit. Tangential vitreous traction on the macula may have caused the CME in the right eye. The shallow PVD over the fovea might have released the tangential vitreous traction from the fovea, induced spontaneous resolution of the CME, and improved the BCVA in the left eye.Keywords: retinitispigmentosa, cystoid macular edema, posterior vitreous detachment, posterior vitreoschisis, optical coherence tomography

The aim of the present work was to identify and characterize large rearrangements involving the USH2A gene in patients with Usher syndrome and nonsyndromic retinitispigmentosa. The multiplex ligation-dependent probe amplification (MLPA) technique combined with a customized array-based comparative genomic hybridization (aCGH) analysis was applied to 40 unrelated patients previously screened for point mutations in the USH2A gene in which none or only one pathologic mutation was identified. We detected six large deletions involving USH2A in six out of the 40 cases studied. Three of the patients were homozygous for the deletion, and the remaining three were compound heterozygous with a previously identified USH2A point mutation. In five of these cases, the patients displayed Usher type 2, and the remaining case displayed nonsyndromic retinitispigmentosa. The exact breakpoint junctions of the deletions found in USH2A in four of these cases were characterized. Our study highlights the need to develop improved efficient strategies of mutation screening based upon next generation sequencing (NGS) that reduce cost, time, and complexity and allow simultaneous identification of all types of disease-causing mutations in diagnostic procedures.

To assess the structure and function of the macula in advanced retinitispigmentosa (RP). Twenty-nine eyes of 22 patients with RP were compared against 17 control eyes. Time-domain optical coherence tomography (OCT) data were processed using OCTRIMA (optical coherence tomography retinal image analysis) as a means of quantifying commercial OCT system images. The thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer and inner plexiform layer complex (GCL+IPL), inner nuclear layer and outer plexiform layer complex (INL+OPL), and the outer nuclear layer (ONL) were measured. Multifocal electroretinography (mfERG) was performed; two groups were formed based on the mfERG findings. Fourteen eyes had no detectable central retinal function (NCRF) on mfERG; detectable but abnormal retinal function (DRF) was present in the mfERG of the other 15 eyes. The thickness of the ONL in the central macular region was significantly less in the NCRF eyes compared with that in both DRF eyes and controls. The ONL was significantly thinner in the pericentral region in both patient groups compared with that in controls, whereas the thickness of the GCL+IPL and INL+OPL was significantly decreased only in the NCRF eyes. The RNFL in the peripheral region was significantly thicker, whereas the thickness of the GCL+IPL and ONL was significantly thinner in both patient groups compared with that in controls. The results are consistent with degeneration of the outer retina preceding inner retinal changes in RP. OCT image segmentation enables objective evaluation of retinal structural changes in RP, with potential use in the planning of therapeutic interventions and conceivably as an outcome measure.

Purpose. To assess the structure and function of the macula in advanced retinitispigmentosa (RP). Methods. Twenty-nine eyes of 22 patients with RP were compared against 17 control eyes. Time-domain optical coherence tomography (OCT) data were processed using OCTRIMA (optical coherence tomography retinal image analysis) as a means of quantifying commercial OCT system images. The thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer and inner plexiform layer complex (GCL+IPL), inner nuclear layer and outer plexiform layer complex (INL+OPL), and the outer nuclear layer (ONL) were measured. Multifocal electroretinography (mfERG) was performed; two groups were formed based on the mfERG findings. Fourteen eyes had no detectable central retinal function (NCRF) on mfERG; detectable but abnormal retinal function (DRF) was present in the mfERG of the other 15 eyes. Results. The thickness of the ONL in the central macular region was significantly less in the NCRF eyes compared with that in both DRF eyes and controls. The ONL was significantly thinner in the pericentral region in both patient groups compared with that in controls, whereas the thickness of the GCL+IPL and INL+OPL was significantly decreased only in the NCRF eyes. The RNFL in the peripheral region was significantly thicker, whereas the thickness of the GCL+IPL and ONL was significantly thinner in both patient groups compared with that in controls. Conclusions. The results are consistent with degeneration of the outer retina preceding inner retinal changes in RP. OCT image segmentation enables objective evaluation of retinal structural changes in RP, with potential use in the planning of therapeutic interventions and conceivably as an outcome measure. PMID:21948552

To determine macular pigment (MP) in patients with inherited retinal degeneration and the response of MP and vision to supplementation of lutein. Patients with retinitispigmentosa (RP) or Usher syndrome and normal subjects had MP optical density profiles measured with heterochromatic flicker photometry. Serum carotenoids, visual acuity, foveal sensitivity, and retinal thickness (by optical coherence tomography [OCT]) were quantified. The effects on MP and central vision of 6 months of lutein supplementation at 20 mg/d were determined. MP density in the patients as a group did not differ from normal. Among patients with lower MP, there was a higher percentage of females, smokers, and light-colored irides. Disease expression tended to be more severe in patients with lower MP. Inner retinal thickness by OCT correlated positively with MP density in the patients. After supplementation, all participants showed an increase in serum lutein. Only approximately half the patients showed a statistically significant increase in MP. Retinal nonresponders had slightly greater disease severity but were otherwise not distinguishable from responders. Central vision was unchanged after supplementation. Factors previously associated with lower or higher MP density in normal subjects showed similar associations in RP and Usher syndrome. In addition, MP in patients may be affected by stage of retinal disease, especially that leading to abnormal foveal architecture. MP could be augmented by supplemental lutein in many but not all patients. There was no change in central vision after 6 months of lutein supplementation, but long-term influences on the natural history of these retinal degenerations require further study.

Full Text Available PURPOSE: To study the association between retinitispigmentosa (RP and the progression of diabetic retinopathy (DR. METHODS: Using the Longitudinal Health Insurance Database 2000 of Taiwan, we identified individuals with an initial diagnosis for RP during the period of 1997-2008. A non-RP comparison group, 10-fold frequency matched by sex, age, index year and the year of diabetes diagnosed, were randomly selected from the same database. The occurrence of DR was observed for all subjects until the end of 2009. The Kaplan-Meier curves were used to illustrate the cumulative probability of developing DR for the RP group and comparison groups. The hazard ratio (HR of DR for the RP group relative to the comparison group was estimated using Cox proportional hazards model after adjusting for potential confounders. RESULTS: The Kaplan-Meier curves were not statistically significant different between the RP group and the comparison group. However, the RP group had a higher cumulative probability of developing DR during the first six to seven years. The cumulative probability kept increasing and became higher in the comparison group but remained unchanged in the RP group. The HR for the RP patients comparing with the comparison group was 0.96 (95% confidence interval (CI = 0.43-2.14. Stratified by severity, RP was associated with a non-statistically significant reduced risk of proliferative DR (PDR (HR = 0.70, 95% CI = 0.16-3.14. The HR for non-proliferative DR (NPDR was 1.08 (95% CI = 0.40-2.86. CONCLUSION: In this study, RP was not statistically significant associated with the incidence of DR.

DNA diagnosis of X-linked retinitispigmentosa (XLRP) is hampered by its genetic heterogeneity, while a clinical subdivision is almost impossible to make. So far, diagnostic services have been offered only to those families in which linkage to one RP locus (RP2 or RP3) has been clearly established.

Purpose: To identify disease-causing mutations in a Chinese patient with retinitispigmentosa (RP). Methods: A detailed clinical examination was performed on the proband. Targeted next-generation sequencing (NGS) combined with bioinformatics analysis was performed on the proband to detect candidate...

mitochondrial point mutation, m.8989G>C, in a patient presenting with neuropathy, ataxia and retinitispigmentosa constituting the classical NARP phenotype. This mutation alters the amino acid right next to canonical NARP mutation. We suggest that classic NARP syndrome relates to a defined dysfunction of p...

Autosomal recessive Stargardt disease is caused by mutations in the ABCA4 gene. Mutations in ABCA4 are also found in two-thirds of cases with autosomal recessive cone-rod dystrophy, and a small fraction of patients with autosomal recessive retinitispigmentosa. Patients with autosomal recessive

A single-nucleotide mutation in the gene that encodes DHDDS has been identified by whole exome sequencing as the cause of the non-syndromic recessive retinitispigmentosa (RP) in a family of Ashkenazi Jewish origin in which three of the four siblings have early onset retinal degeneration. The peripheral retinal degeneration in the affected siblings was evident in the initial examination in 1992 and only one had detectable electroretinogram (ERG) that suggested cone-rod dysfunction. The pigmentary retinal degeneration subsequently progressed rapidly. The identified mutation changes the highly conserved residue Lys42 to Glu, resulting in lower catalytic efficiency. Patterns of plasma transferrin isoelectric focusing gel were normal in all family members, indicating no significant abnormality in protein glycosylation. Dolichols have been shown to influence the fluidity and of the membrane and promote vesicle fusion. Considering that photoreceptor outer segments contain stacks of membrane discs, we believe that the mutation may lead to low dolichol levels in photoreceptor outer segments, resulting in unstable membrane structure that leads to photoreceptor degeneration.

Hereditary retinal diseases are now the leading cause of blindness certification in the working age population (age 16–64 years) in England and Wales, of which retinitispigmentosa (RP) is the most common disorder. RP may be complicated by cystoid macular oedema (CMO), causing a reduction of central vision. The underlying pathogenesis of RP-associated CMO (RP-CMO) remains uncertain, however, several mechanisms have been proposed, including: (1) breakdown of the blood-retinal barrier, (2) failure (or dysfunction) of the pumping mechanism in the retinal pigment epithelial, (3) Müller cell oedema and dysfunction, (4) antiretinal antibodies and (5) vitreous traction. There are limited data on efficacy of treatments for RP-CMO. Treatments attempted to date include oral and topical carbonic anhydrase inhibitors, oral, topical, intravitreal and periocular steroids, topical non-steroidal anti-inflammatory medications, photocoagulation, vitrectomy with internal limiting membrane peel, oral lutein and intravitreal antivascular endothelial growth factor injections. This review summarises the evidence supporting these treatment modalities. Successful management of RP-CMO should aim to improve both quality and quantity of vision in the short term and may also slow central vision loss over time. PMID:27913439

NR2E3, also called photoreceptor-specific nuclear receptor (PNR), is a transcription factor of the nuclear hormone receptor superfamily whose expression is uniquely restricted to photoreceptors. There, its physiological activity is essential for proper rod and cone photoreceptor development and maintenance. Thirty-two different mutations in NR2E3 have been identified in either homozygous or compound heterozygous state in the recessively inherited enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), and clumped pigmentary retinal degeneration (CPRD). The clinical phenotype common to all these patients is night blindness, rudimental or absent rod function, and hyperfunction of the "blue" S-cones. A single p.G56R mutation is inherited in a dominant manner and causes retinitispigmentosa (RP). We have established a new locus-specific database for NR2E3 (www.LOVD.nl/eye), containing all reported mutations, polymorphisms, and unclassified sequence variants, including novel ones. A high proportion of mutations are located in the evolutionarily-conserved DNA-binding domains (DBDs) and ligand-binding domains (LBDs) of NR2E3. Based on homology modeling of these NR2E3 domains, we propose a structural localization of mutated residues. The high variability of clinical phenotypes observed in patients affected by NR2E3-linked retinal degenerations may be caused by different disease mechanisms, including absence of DNA-binding, altered interactions with transcriptional coregulators, and differential activity of modifier genes.

Purpose To determine the rate of progression and optimal follow up time in patients with advanced stage retinitispigmentosa (RP) comparing the use of fundus autofluorescence imaging and spectral domain optical coherence tomography. Design Retrospective analysis of progression rate. Methods Longitudinal imaging follow up in 71 patients with retinitispigmentosa was studied using the main outcome measurements of hyperautofluoresent ring horizontal diameter and vertical diameter along with ellipsoid zone line width from spectral domain optical coherence tomography. Test-retest reliability and the rate of progression were calculated. The interaction between the progression rates was tested for sex, age, mode of inheritance, and baseline measurement size. Symmetry of left and right eye progression rate was also tested. Results Significant progression was observed in >75% of patients during the 2 year mean follow up. The mean annual progression rates of ellipsoid zone line, and hyperautofluorescent ring horizontal diameter and vertical diameter were 0.45° (4.9%), 0.51° (4.1%), and 0.42° (4.0%), respectively. The e llipsoid zone line width, and hyperautofluorescent ring horizontal diameter and vertical diameter had low test-retest variabilities of 8.9%, 9.5% and 9.6%, respectively. This study is the first to demonstrate asymmetrical structural progression rate between right and left eye, which was found in 19% of patients. The rate of progression was significantly slower as the disease approached the fovea, supporting the theory that RP progresses in an exponential fashion. No significant interaction between progression rate and patient age, sex, or mode of inheritance was observed. Conclusions Fundus autofluorescence and optical coherence tomography detect progression in patients with RP reliably and with strong correlation. These parameters may be useful alongside functional assessments as the outcome measurements for future therapeutic trials. Follow-up at 1 year

Retinitispigmentosa (RP) is a genetically heterogeneous disease characterized by degeneration of the retina. A mutation in a new ceramide kinase (CERK) homologous gene, named CERK-like protein (CERKL), was found to cause autosomal recessive retinitispigmentosa (RP26). Here, we show a point mutation of one of two putative nuclear localization signal (NLS) sequences inhibited the nuclear localization of the protein. Furthermore, the tetra-GFP-tagged NLS, which cannot passively enter the nucleus, was observed not only in the nucleus but also in the nucleolus. Our results provide First evidence of the active nuclear import of CERKL and suggest that the identified NLS might be responsible for nucleolar retention of the protein. As recent studies have shown other RP-related proteins are localized in the nucleus or the nucleolus, our identification of NLS in CERKL suggests that CERKL likely plays important roles for retinal functions in the nucleus and the nucleolus

This study was carried out to evaluate the progression of visual function impairment in carriers of X-linked recessive retinitispigmentosa. We also assessed the relationship between the retinal findings at presentation and the extent of deterioration. Observational, retrospective, case series. Twenty-seven carriers of X-linked recessive retinitispigmentosa. Each carrier was clinically categorized into one of four grades (grades 0 through 3) depending on the presence or absence of a tapetal-like retinal reflex and the extent of peripheral pigmentary degeneration. A complete ophthalmologic examination was performed and data for visual acuity, visual field area, and electroretinographic measurements were collected on the most recent visit in both eyes. These were then compared with similar data obtained on their initial visits. A comparison of visual function was carried out between the initial visit and the most recent visit on each carrier. The visual acuity was measured with Snellen's acuity charts. The visual fields to targets V-4-e and II-4-e were planimeterized and used for the analysis. The electroretinographic (ERG) measures used were light-adapted single-flash b-wave amplitudes and 30-Hz red flicker for cone function, dark-adapted maximal b-wave amplitudes, and response to a low intensity blue-flash for rod function. None of the 11 carriers with a tapetal-like reflex only (grade 1) showed any significant change in visual acuity or fields as compared with 3 of 7 (43%) carriers with diffuse peripheral pigmentary findings (grade 3) who showed significant deterioration in visual acuity in at least one eye, and 6 of 7 (86%) who showed a significant decrease in visual field area with at least one target size in at least one eye. By comparison, only 1 of 10 carriers with a grade 1 fundus finding demonstrated a significant decrease in maximal dark-adapted ERG function as compared with 5 of 6 (83%) carriers with grade 3 in response to a single-flash stimulus and

Inherited retinal diseases are thought to be the leading cause of sight loss in the working age population. Mutations found in the RPGR and CHM genes cause retinitispigmentosa (RP) and choroideremia, respectively. In the first instance, an X-linked family history of visual field loss commonly raises the suspicion of one of these two genes. In choroideremia, the classic description of a white fundal reflex secondary to the widespread chorioretinal degeneration was made over a hundred years ago in Caucasians. But, it is not so obvious in heavily pigmented fundi. Hence, the clinical diagnosis of CHM in non-Caucasian patients may be challenging in the first stages of the disease. Here we report a case of a Southeast Asian gentleman who has a family history of X-linked retinal degeneration and was found to have a confirmed in-frame deletion of 12 DNA nucleotides in exon 15 of the RPGR gene. Later in life, however, his fundal appearance showed unusual areas of circular pigment hypertrophy and clumping. He was therefore tested for carrying a disease-causing mutation in the CHM gene and a null mutation was found. Since gene therapy trials are ongoing for both of these conditions, it has now become critically important to establish the correct genetic diagnosis in order to recruit suitable candidates. Moreover, this case demonstrates the necessity to remain vigilant in the interpretation of genetic results which are inconsistent with clinical features.

To review the visual status and clinical presentation of patients with retinitispigmentosa (RP). Multicenter, retrospective, and analytical review was conducted of the visual status and clinical characteristics of patients with RP at first presentation from January 2007 to December 2011. Main outcome measure was the World Health Organization's visual status classification in relation to sex and age at presentation. Data analysis by SPSS (version 15) and statistical significance was assumed at Ppresent in their siblings 15 (71.4%), grandparents 11 (52.3%), and parents 4 (19.4%). Forty (41.7%) were blind at presentation and 23 (24%) were visually impaired. Blindness in six (15%) patients was secondary to glaucoma. Retinal vascular narrowing and retinal pigmentary changes of varying severity were present in all patients. Thirty-five (36.5%) had maculopathy, 36 (37.5%) refractive error, 19 (20%) lenticular opacities, and eleven (11.5%) had glaucoma. RP was typical in 85 patients (88.5%). Older patients had higher rates of blindness at presentation (P=0.005); blindness and visual impairment rate at presentation were higher in males than females (P=0.029). Clinical presentation with advanced diseases, higher blindness rate in older patients, sex-related difference in blindness/visual impairment rates, as well as high glaucoma blindness in RP patients requires urgent attention in southwestern Nigeria.

A case of Laurence-Moon-Biedl-Bardet syndrome in a patient undergoing hemodialysis is reported. The principal characteristics of this congenital syndrome are described. A possible pathogenetic mechanism of the atypical form of retinitispigmentosa (sine pigmento) is discussed.

Full Text Available Next-generation sequencing has become more widely used to reveal genetic defect in monogenic disorders. Retinitispigmentosa (RP, the leading cause of hereditary blindness worldwide, has been attributed to more than 67 disease-causing genes. Due to the extreme genetic heterogeneity, using general molecular screening alone is inadequate for identifying genetic predispositions in susceptible individuals. In order to identify underlying mutation rapidly, we utilized next-generation sequencing in a four-generation Chinese family with RP. Two affected patients and an unaffected sibling were subjected to whole exome sequencing. Through bioinformatics analysis and direct sequencing confirmation, we identified p.R135W transition in the rhodopsin gene. The mutation was subsequently confirmed to cosegregate with the disease in the family. In this study, our results suggest that whole exome sequencing is a robust method in diagnosing familial hereditary disease.

Microdeletions Glu767(1-bp del), Thr967(1-bp del), and Leu1446(2-bp del) in the human USH2A gene have been reported to cause Usher syndrome type II, a disorder characterized by retinitispigmentosa (RP) and mild-to-severe hearing loss. Each of these three frameshift mutations is predicted to lead to an unstable mRNA transcript that, if translated, would result in a truncated protein lacking the carboxy terminus. Here, we report Cys759Phe, a novel missense mutation in this gene that changes an amino-acid residue within the fifth laminin-epidermal growth factor-like domain of the USH2A gene and that is associated with recessive RP without hearing loss. This single mutation was found in 4.5% of 224 patients with recessive RP, suggesting that USH2A could cause more cases of nonsyndromic recessive RP than does any other gene identified to date.

Usher syndrome is an autosomal recessive condition characterized by retinitispigmentosa (RP) and congenital hearing loss, with or without vestibular dysfunction. Allelic variants of CDH23 cause both Usher syndrome type 1D (USH1D) and a form of nonsyndromic hearing loss (DFNB12). The authors describe here a 34-year-old patient with congenital hearing loss and a new diagnosis of sector RP who was found to have two novel compound heterozygous mutations in CDH23, including one missense (c.8530C > A; p.Pro2844Thr) and one splice-site (c.5820 + 5G > A) mutation. This is the first report of sector RP associated with these types of mutations in CDH23. Copyright 2016, SLACK Incorporated.

Full Text Available X-linked RetinitisPigmentosa (XLRP accounts for 10-20% of all RP cases, and represents the most severe subtype of this disease. Mutations in the RetinitisPigmentosa GTPase Regulator (RPGR gene are the most common causes of XLRP, accounting for over 70-75% of all XLRP cases. In this work, we analyzed all the exons of RPGR gene with Sanger sequencing in seven Chinese XLRP families, two of these with a provisional diagnosis of adRP but without male-to-male transmission. Three novel deletions (c.2233_34delAG; c.2236_37delGA and c.2403_04delAG and two known nonsense mutations (c.851C→G and c.2260G→T were identified in five families. Two novel deletions (c.2233_34delAG and c.2236_37delGA resulted in the same frame shift (p.E746RfsX22, created similar phenotype in Family 3 and 4. The novel deletion (c.2403_04delAG; p.E802GfsX31 resulted in both XLRP and x-linked cone-rod dystrophy within the male patients of family 5, which suggested the presence of either genetic or environmental modifiers, or both, play a substantial role in disease expression. Genotype-phenotype correlation analysis suggested that (1 both patients and female carriers with mutation in Exon 8 (Family 1 manifest more severe disease than did those with ORF15 mutations (Family 2&3&4; (2 mutation close to downstream of ORF15 (Family 5 demonstrate the early preferential loss of cone function with moderate loss of rod function.

X-linked RetinitisPigmentosa (XLRP) accounts for 10-20% of all RP cases, and represents the most severe subtype of this disease. Mutations in the RetinitisPigmentosa GTPase Regulator (RPGR) gene are the most common causes of XLRP, accounting for over 70-75% of all XLRP cases. In this work, we analyzed all the exons of RPGR gene with Sanger sequencing in seven Chinese XLRP families, two of these with a provisional diagnosis of adRP but without male-to-male transmission. Three novel deletions (c.2233_34delAG; c.2236_37delGA and c.2403_04delAG) and two known nonsense mutations (c.851C→G and c.2260G→T) were identified in five families. Two novel deletions (c.2233_34delAG and c.2236_37delGA) resulted in the same frame shift (p.E746RfsX22), created similar phenotype in Family 3 and 4. The novel deletion (c.2403_04delAG; p.E802GfsX31) resulted in both XLRP and x-linked cone-rod dystrophy within the male patients of family 5, which suggested the presence of either genetic or environmental modifiers, or both, play a substantial role in disease expression. Genotype-phenotype correlation analysis suggested that (1) both patients and female carriers with mutation in Exon 8 (Family 1) manifest more severe disease than did those with ORF15 mutations (Family 2&3&4); (2) mutation close to downstream of ORF15 (Family 5) demonstrate the early preferential loss of cone function with moderate loss of rod function.

Purpose To identify pathogenic mutations responsible for autosomal recessive retinitispigmentosa (arRP) in consanguineous familial cases. Methods Seven large familial cases with multiple individuals diagnosed with retinitispigmentosa were included in the study. Affected individuals in these families underwent ophthalmic examinations to document the symptoms and confirm the initial diagnosis. Blood samples were collected from all participating members, and genomic DNA was extracted. An exclusion analysis with microsatellite markers spanning the TULP1 locus on chromosome 6p was performed, and two-point logarithm of odds (LOD) scores were calculated. All coding exons along with the exon–intron boundaries of TULP1 were sequenced bidirectionally. We constructed a single nucleotide polymorphism (SNP) haplotype for the four familial cases harboring the K489R allele and estimated the likelihood of a founder effect. Results The ophthalmic examinations of the affected individuals in these familial cases were suggestive of RP. Exclusion analyses confirmed linkage to chromosome 6p harboring TULP1 with positive two-point LOD scores. Subsequent Sanger sequencing identified the single base pair substitution in exon14, c.1466A>G (p.K489R), in four families. Additionally, we identified a two-base deletion in exon 4, c.286_287delGA (p.E96Gfs77*); a homozygous splice site variant in intron 14, c.1495+4A>C; and a novel missense variation in exon 15, c.1561C>T (p.P521S). All mutations segregated with the disease phenotype in the respective families and were absent in ethnically matched control chromosomes. Haplotype analysis suggested (p<10−6) that affected individuals inherited the causal mutation from a common ancestor. Conclusions Pathogenic mutations in TULP1 are responsible for the RP phenotype in seven familial cases with a common ancestral mutation responsible for the disease phenotype in four of the seven families. PMID:27440997

High-contrast figures such as Landolt rings are insufficient to evaluate the function of the foveal cones of retinitispigmentosa (RP) patients. We investigated the correlation between visual function as determined with Landolt rings and with the Vistech Contrast Sensitivity Function Test (VCTS) at various spatial frequencies, in addition to the Cambridge Low Contrast Grating (CLCG). The study included 30 retinitispigmentosa patients (53 eyes). All patients were assessed with Landolt rings, the Vistech method, and the CLCG. We estimated the relative contribution of contrast sensitivity to visual acuity by VCTS at each spatial frequency and by CLCG by simple linear regression analysis. The results of the regression analysis of VCTS at 1.5, 3.0, and 6.0 cycles/degree showed a significant correlation between Landolt rings and VCTS and between CLCG and VCTS that was strongest at 6.0 cycles/degree. There was no significant correlation between Landolt rings and VCTS or between CLCG and VCTS at 12.0 and 18.0 cycles/degree. Patients with a visual acuity of 20/25 and CLCG greater than 100 were divided into two groups according to their contrast sensitivity at 18.0 cycles/degree on VCTS. The VCTS at the highest frequency was useful for evaluating the foveal visual function in RP patients having good visual acuity with the Landolt rings. Thus, contrast sensitivity should be useful in detecting minute impairment or improvement of visual function in RP. Copyright 2002 S. Karger AG, Basel

Abstract The aim of this study was to examine changes in photoreceptor ellipsoid zone (EZ) and postreceptor retinal layer in retinitispigmentosa (RP) patients by ganglion cell analysis (GCA) combined with optical coherence tomography (OCT) imaging to evaluate the structure–function relationships between retinal layer changes and best corrected visual acuity (BCVA). Sixty-eight eyes of 35 patients with RP and 65 eyes of 35 normal controls were analyzed in the study. The average length of EZ was 911.1 ± 208.8 μm in RP patients, which was shortened with the progression of the disease on the OCT images. The average ganglion cell–inner plexiform layer thickness (GCIPLT) was 54.7 ± 18.9 μm in RP patients, while in normal controls it was 85.6 ± 6.8 μm. The GCIPLT in all quarters became significantly thinner along with outer retinal thinning. There was a significantly positive correlation between BCVA and EZ (r = −0.7622, P retinal layer changes from a new perspective in RP patients, which suggests that EZ and GCIPLT obtained by GCA combined with OCT imaging are the direct and valid indicators to diagnosis and predict the pathological process of RP. PMID:28033301

Full Text Available Oluwatoyin Helen Onakpoya,1 Caroline Olufunlayo Adeoti,2 Tunji Sunday Oluleye,3 Iyiade Adeseye Ajayi,4 Timothy Majengbasan,4,5 Olayemi Kolawole Olorundare1 1Department of Ophthalmology, Obafemi Awolowo University Teaching Hospital, Ile-Ife, 2Department of Ophthalmology, Ladoke Akintola University of Technology Teaching Hospital, Osogbo, 3Department of Ophthalmology, University College Hospital, Ibadan, 4Department of Ophthalmology, University Teaching Hospital, Ado-Ekiti, 5Department of Ophthalmology, Federal Medical Centre, Ido-Ekiti, Nigeria Background: To review the visual status and clinical presentation of patients with retinitispigmentosa (RP.Methodology: Multicenter, retrospective, and analytical review was conducted of the visual status and clinical characteristics of patients with RP at first presentation from January 2007 to December 2011. Main outcome measure was the World Health Organization’s visual status classification in relation to sex and age at presentation. Data analysis by SPSS (version 15 and statistical significance was assumed at P<0.05.Results: One hundred and ninety-two eyes of 96 patients with mean age of 39.08±18.5 years and mode of 25 years constituted the study population; 55 (57.3% were males and 41 (42.7% females. Loss of vision 67 (69.8% and night blindness 56 (58.3% were the leading symptoms. Twenty-one (21.9% patients had a positive family history, with RP present in their siblings 15 (71.4%, grandparents 11 (52.3%, and parents 4 (19.4%. Forty (41.7% were blind at presentation and 23 (24% were visually impaired. Blindness in six (15% patients was secondary to glaucoma. Retinal vascular narrowing and retinal pigmentary changes of varying severity were present in all patients. Thirty-five (36.5% had maculopathy, 36 (37.5% refractive error, 19 (20% lenticular opacities, and eleven (11.5% had glaucoma. RP was typical in 85 patients (88.5%. Older patients had higher rates of blindness at presentation (P=0

To define ophthalmic findings in a family with autosomal dominant retinitispigmentosa and a novel IMPDH1 gene mutation. Genetic and observational family study. Sixteen affected members of a family with autosomal dominant retinitispigmentosa. Ophthalmic examination, including best-corrected visual acuity (VA), slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, Goldmann kinetic perimetry, and electroretinography were performed. Deoxyribonucleic acid single-strand conformation polymorphism (SSCP) analysis was done. Abnormal polymerase chain reaction products identified by SSCP analysis were sequenced bidirectionally. All affected patients had the onset of night blindness within the first decade of life. Ocular findings were characterized by diffuse retinal pigmentary degenerative changes, marked restriction of peripheral visual fields, severe loss of VA, nondetectable electroretinography amplitudes, and a high frequency of posterior subcapsular lens opacities. Affected members were observed to harbor a novel IMPDH1 gene mutation. A novel IMPDH1 gene mutation (Arg231Pro) was associated with a severe form of autosomal dominant retinitispigmentosa. Families affected with a severe form of this genetic subtype should be investigated for a mutation in the IMPDH1 gene.

This case report describes the effects of low-level laser therapy (LLLT) in a single patient with retinitispigmentosa (RP). RP is a heritable disorder of the retina, which eventually leads to blindness. No therapy is currently available. LLLT was applied using a continuous wave laser diode (780 nm, 10 mW average output at 292 Hz, 50% pulse modulation). The complete retina of eyes was irradiated through the conjunctiva for 40 sec (0.4 J, 0.333 W/cm2) two times per week for 2 weeks (1.6 J). A 55-year-old male patient with advanced RP was treated and followed for 7 years. The patient had complained of nyctalopia and decreasing vision. At first presentation, best visual acuity was 20/50 in each eye. Visual fields were reduced to a central residual of 5 degrees. Tritan-dyschromatopsy was found. Retinal potential was absent in electroretinography. Biomicroscopy showed optic nerve atrophy, and narrow retinal vessels with a typical pattern of retinal pigmentation. After four initial treatments of LLLT, visual acuity increased to 20/20 in each eye. Visual fields normalized except for a mid-peripheral absolute concentric scotoma. Five years after discontinuation of LLLT, a relapse was observed. LLLT was repeated (another four treatments) and restored the initial success. During the next 2 years, 17 additional treatments were performed on an "as needed" basis, to maintain the result. LLLT was shown to improve and maintain vision in a patient with RP, and may thereby have contributed to slowing down blindness.

Retinitispigmentosa (RP) refers to a group of inherited retinal degenerations resulting form rod and cone photoreceptor cell death. The rod cell death due to deleterious genetic mutations has been shown to occur mainly through apoptosis, whereas the mechanisms and features of the secondary cone cell death have not been fully elucidated. Our previous study showed that the cone cell death in rd10 mice, an animal model of RP, involves necrotic features and is partly mediated by the receptor interacting protein kinase. However, the relevancy of necrotic cone cell death in human RP patients remains unknown. In the present study, we showed that dying cone cells in rd10 mice exhibited cellular enlargement, along with necrotic changes such as cellular swelling and mitochondrial rupture. In human eyes, live imaging of cone cells by adaptive optics scanning laser ophthalmoscopy revealed significantly increased percentages of enlarged cone cells in the RP patients compared with the control subjects. The vitreous of the RP patients contained significantly higher levels of high-mobility group box-1, which is released extracellularly associated with necrotic cell death. These findings suggest that necrotic enlargement of cone cells is involved in the process of cone degeneration, and that necrosis may be a novel target to prevent or delay the loss of cone-mediated central vision in RP. PMID:27551484

Retinitispigmentosa (RP) is associated with the formation of a posterior subcapsular cataract (PSC). As only a small part of the crystalline lens is usually affected, it is sometimes difficult to determine to what extent the visual loss is caused by the PSC alone. The methodology was developed in analogy to a scoring system for posterior capsule opacification by Tetz et al. Following dilation of the pupil, standardized photographs of the anterior segments were obtained utilizing a Zeiss photoslitlamp model 40 SL/P. The PSC was scored by evaluating retroillumination photographs. The individual PSC index was calculated by multiplying the density of the opacification (graded from 0 to 4) by the area involved in the central 4 mm zone of the pupil (calculated between 0 and 1). For testing the reliability of the evaluation system in part 1 of this study, 11 RP patients with different grades of PSC were examined by three independent observers. In part 2 of this study 37 eyes of 24 RP patients, aged 47.2 +/- 11.8 years, were evaluated and the PSC index was correlated with different parameters (visual acuity, age, visual fields, eletroretinography). RESULTS PART 1: The cataract-density grades were between 1 and 4 in the 11 patients. In relation to the central 4-mm pupillary zone between 13 and 100% of the area were opacified. Cataract indices (density x area) were between 0.13 and 4.0 (Mean values: Examiner 1:1.41 +/- 1.49; Examiner 2:1.28 +/- 1.46; Examiner 3:1.22 +/- 1.44; differences not significant: P = 0.77). PART 2: After an average duration of RP of 23 years, the average cataract index of the 24 patients was 1.72 +/- 1.35. There was no correlation between cataract index and ERG or visual fields (r 0.4); however, there was a good correlation to visual acuity (r = -0.72; P = 0.0001). Patients with early onset of RP (before 20th year of life) presented on average with an higher cataract index (2.06 +/- 1.67) compared to patients with late manifestation (0.61 +/- 0

To report a possible rare association of bilateral retinitispigmentosa inversa (RPI) with unilateral high myopia with fellow eye optic disc pitting. A 55-year-old man with a history of reduced vision in the right eye since childhood presented with gradually decreasing vision in the left eye. On examination, a -23.00 diopter refractive error and diffuse chorioretinal atrophy consistent with pathologic myopia was found in the right eye. An optic disc pit with posterior pole pigmentary alterations thought to be consequent to a previous neurosensory detachment was found in the left eye. Though the retinal arteriolar attenuation seen in both eyes with an inconsistent history of night blindness since childhood pointed towards the possibility of a concurrently existing rod or rod-cone dystrophy, the posterior pole pigmentary alterations characteristic of RPI were clearly masked by the above pathologies. Optical coherence tomography demonstrated prominent foveal atrophy and an optic disc pit in the left eye. Electroretinography (ERG) demonstrated moderately attenuated amplitudes with prolonged implicit times of rod and cone responses bilaterally. The patient was diagnosed with bilateral RPI and anisometropic amblyopia in the right eye. This report documents a unique constellation of findings which include bilateral RPI and unilateral high myopia with an optic disc pit in the fellow eye. An ERG confirmation of a dystrophic etiology should be sought in suspicious cases, especially when findings are masked by the concurrent presence of other pathologies.

Purpose Autosomal recessive retinitispigmentosa (arRP) is a genetically heterogeneous disease resulting in progressive loss of photoreceptors that leads to blindness. To date, 36 genes are known to cause arRP, rendering the molecular diagnosis a challenge. The aim of this study was to use homozygosity mapping to identify the causative mutation in a series of inbred families with arRP. Methods arRP patients underwent standard ophthalmic examination, Goldman perimetry, fundus examination, retinal OCT, autofluorescence measurement, and full-field electroretinogram. Fifteen consanguineous families with arRP excluded for USH2A and EYS were genotyped on 250 K SNP arrays. Homozygous regions were listed, and known genes within these regions were PCR sequenced. Familial segregation and mutation analyzes were performed. Results We found ten mutations, seven of which were novel mutations in eight known genes, including RP1, IMPG2, NR2E3, PDE6A, PDE6B, RLBP1, CNGB1, and C2ORF71, in ten out of 15 families. The patients carrying RP1, C2ORF71, and IMPG2 mutations presented with severe RP, while those with PDE6A, PDE6B, and CNGB1 mutations were less severely affected. The five families without mutations in known genes could be a source of identification of novel genes. Conclusions Homozygosity mapping combined with systematic screening of known genes results in a positive molecular diagnosis in 66.7% of families. PMID:24339724

Three dimensional segmentation of macular optical coherence tomography (OCT) data of subjects with retinitispigmentosa (RP) is a challenging problem due to the disappearance of the photoreceptor layers, which causes algorithms developed for segmentation of healthy data to perform poorly on RP patients. In this work, we present enhancements to a previously developed graph-based OCT segmentation pipeline to enable processing of RP data. The algorithm segments eight retinal layers in RP data by relaxing constraints on the thickness and smoothness of each layer learned from healthy data. Following from prior work, a random forest classifier is first trained on the RP data to estimate boundary probabilities, which are used by a graph search algorithm to find the optimal set of nine surfaces that fit the data. Due to the intensity disparity between normal layers of healthy controls and layers in various stages of degeneration in RP patients, an additional intensity normalization step is introduced. Leave-one-out validation on data acquired from nine subjects showed an average overall boundary error of 4.22 μm as compared to 6.02 μm using the original algorithm.

RetinitisPigmentosa (RP) is the most common form of inherited retinal dystrophy caused by different genetic variants. More than 60 causative genes have been identified to date. The establishment of cost-effective molecular diagnostic tests with high sensitivity and specificity can be beneficial for patients and clinicians. Here, we developed a clinical diagnostic test for RP in the Japanese population. Evaluation of diagnostic technology, Prospective, Clinical and experimental study. A panel of 39 genes reported to cause RP in Japanese patients was established. Next generation sequence (NGS) technology was applied for the analyses of 94 probands with RP and RP-related diseases. After interpretation of detected genetic variants, molecular diagnosis based on a study of the genetic variants and a clinical phenotype was made by a multidisciplinary team including clinicians, researchers and genetic counselors. NGS analyses found 14,343 variants from 94 probands. Among them, 189 variants in 83 probands (88.3% of all cases) were selected as pathogenic variants and 64 probands (68.1%) have variants which can cause diseases. After the deliberation of these 64 cases, molecular diagnosis was made in 43 probands (45.7%). The final molecular diagnostic rate with the current system combining supplemental Sanger sequencing was 47.9% (45 of 94 cases). The RP panel provides the significant advantage of detecting genetic variants with a high molecular diagnostic rate. This type of race-specific high-throughput genotyping allows us to conduct a cost-effective and clinically useful genetic diagnostic test.

Full Text Available Retinitispigmentosa (RP is a highly heterogeneous genetic visual disorder with more than 70 known causative genes, some of them shared with other non-syndromic retinal dystrophies (e.g. Leber congenital amaurosis, LCA. The identification of RP genes has increased steadily during the last decade, and the 30% of the cases that still remain unassigned will soon decrease after the advent of exome/genome sequencing. A considerable amount of genetic and functional data on single RD genes and mutations has been gathered, but a comprehensive view of the RP genes and their interacting partners is still very fragmentary. This is the main gap that needs to be filled in order to understand how mutations relate to progressive blinding disorders and devise effective therapies.We have built an RP-specific network (RPGeNet by merging data from different sources: high-throughput data from BioGRID and STRING databases, manually curated data for interactions retrieved from iHOP, as well as interactions filtered out by syntactical parsing from up-to-date abstracts and full-text papers related to the RP research field. The paths emerging when known RP genes were used as baits over the whole interactome have been analysed, and the minimal number of connections among the RP genes and their close neighbors were distilled in order to simplify the search space.In contrast to the analysis of single isolated genes, finding the networks linking disease genes renders powerful etiopathological insights. We here provide an interactive interface, RPGeNet, for the molecular biologist to explore the network centered on the non-syndromic and syndromic RP and LCA causative genes. By integrating tissue-specific expression levels and phenotypic data on top of that network, a more comprehensive biological view will highlight key molecular players of retinal degeneration and unveil new RP disease candidates.

To identify mutations in the AIPL1, CRB1, GUCY2D, RPE65, and RPGRIP1 genes in patients with juvenile retinitispigmentosa. Mutation analysis was carried out in a group of 35 unrelated patients with juvenile autosomal recessive retinitispigmentosa (ARRP), Leber's congenital amaurosis (LCA), or juvenile isolated retinitispigmentosa (IRP), by denaturing high performance liquid chromatography followed by direct sequencing. All three groups of patients showed typical combinations of eye signs associated with retinitispigmentosa: pale optic discs, narrow arterioles, pigmentary changes, and nystagmus. Mutations were found in 34% of in CRB1 (11%), GUCY2D (11%), RPE65 (6%), and RPGRIP1 (6%). Nine mutations are reported, including a new combination of two mutations in CRB1, and new mutations in GUCY2D and RPGRIP1. The new GUCY2D mutation (c.3283delC, p.Pro1069ArgfsX37) is the first pathological sequence change reported in the intracellular C-terminal domain of GUCY2D, and did not lead to the commonly associated LCA, but to a juvenile retinitispigmentosa phenotype. The polymorphic nature of three previously described (pathological) sequence changes in AIPL1, CRB1, and RPGRIP1 was established. Seven new polymorphic changes, useful for further association studies, were found. New and previously described sequence changes were detected in retinitispigmentosa in CRB1, GUCY2D, and RPGRIP1; and in LCA patients in CRB1, GUCY2D, and RPE65. These data, combined with previous reports, suggest that LCA and juvenile ARRP are closely related and belong to a continuous spectrum of juvenile retinitispigmentosa.

Purpose To evaluate microarray-based genotyping technology for the detection of mutations responsible for retinitispigmentosa (RP) and to perform phenotypic characterization of patients with pathogenic mutations. Methods DNA from 336 patients with RP and 360 controls was analyzed using the GoldenGate assay with microbeads containing 95 previously reported disease-associated mutations from 28 RP genes. Mutations identified by microarray-based genotyping were confirmed by direct sequencing. Segregation analysis and phenotypic characterization were performed in patients with mutations. The disease severity was assessed by visual acuity, electroretinography, optical coherence tomography, and kinetic perimetry. Results Ten RP-related mutations of five RP genes (PRP3 pre-mRNA processing factor 3 homolog [PRPF3], rhodopsin [RHO], phosphodiesterase 6B [PDE6B], peripherin 2 [PRPH2], and retinitispigmentosa 1 [RP1]) were identified in 26 of the 336 patients (7.7%) and in six of the 360 controls (1.7%). The p.H557Y mutation in PDE6B, which was homozygous in four patients and heterozygous in nine patients, was the most frequent mutation (2.5%). Mutation segregation was assessed in four families. Among the patients with missense mutations, the most severe phenotype occurred in patients with p.D984G in RP1; less severe phenotypes occurred in patients with p.R135W in RHO; a relatively moderate phenotype occurred in patients with p.T494M in PRPF3, p.H557Y in PDE6B, or p.W316G in PRPH2; and a mild phenotype was seen in a patient with p.D190N in RHO. Conclusions The results reveal that the GoldenGate assay may not be an efficient method for molecular diagnosis in RP patients with rare mutations, although it has proven to be reliable and efficient for high-throughput genotyping of single-nucleotide polymorphisms. The clinical features varied according to the mutations. Continuous effort to identify novel RP genes and mutations in a population is needed to improve the efficiency and

In a previous study on a large pedigree from a genetically isolated population in the Netherlands, we localized a gene for autosomal recessive retinitispigmentosa with paraarteriolar preservation of the retinal pigment epithelium (PPRPE) on the long arm of chromosome 1. In this study, we present an

The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitispigmentosa. All 22 exons...

To determine the disease expression in autosomal recessive (ar) retinitispigmentosa (RP) caused by mutations in the MAK (male germ cell-associated kinase) gene. Patients with RP and MAK gene mutations (n = 24; age, 32-77 years at first visit) were studied by ocular examination, perimetry, and optical coherence tomography (OCT). All but one MAK patient were homozygous for an identical truncating mutation in exon 9 and had Ashkenazi Jewish heritage. The carrier frequency of this mutation among 1207 unrelated Ashkenazi control subjects was 1 in 55, making it the most common cause of heritable retinal disease in this population and MAK-associated RP the sixth most common Mendelian disease overall in this group. Visual acuities could be normal into the eighth decade of life. Kinetic fields showed early loss in the superior-temporal quadrant. With more advanced disease, superior and midperipheral function was lost, but the nasal field remained. Only a central island was present at late stages. Pigmentary retinopathy was less prominent in the superior nasal quadrant. Rod-mediated vision was abnormal but detectable in the residual field; all patients had rod>cone dysfunction. Photoreceptor layer thickness was normal centrally but decreased with eccentricity. At the stages studied, there was no evidence of photoreceptor ciliary elongation. The patterns of disease expression in the MAK form of arRP showed some resemblance to patterns described in autosomal dominant RP, especially the form caused by RP1 mutations. The similarity in phenotypes is of interest, considering that there is experimental evidence of interaction between Mak and RP1 in the photoreceptor cilium.

To identify the mutation spectrum of phosphodiesterase beta subunit (PDE6B) gene, the incidence in Chinese patients with retinitispigmentosa (RP) and their clinical phenotypic characteristics. Screening of mutations within PDE6B gene was performed using polymerase chain reaction-heteroduplex-single strand conformation polymorphism (PCR-SSCP) and DNA sequence in 35 autosomal recessive (AR) RP and 55 sporadic RP cases. The phenotypes of the patients with the gene mutation were examined and analyzed. Novel complex heterozygous variants of PDE6B gene in a sporadic case, a T to C transversion in codon 323 resulting in the substitution of Gly by Ser and 2 base pairs (bp: G and T) insert between the 27th-28th bp upstream of the 5'-end of exon 10 were both present in a same isolate RP. But they are not found in 100 unrelated healthy individuals. Ocular findings showed diffuse pigmentary retinal degeneration in the midperipheral and peripheral fundi, optic atrophy and vessel attenuation. Multi-focal ERG indicated that the rod function was more severely deteriorated. A mutation was found in a case with RP in a ARRP family, a G to A transversion at 19th base upstream 5'-end of exon 11 (within intron 10) of PDE6B gene. A sporadic RP carried a sequence variant of PDE6B gene, a G to C transition, at the 15th base adjacent to the 3'-end of exon l8. In another isolate case with RP was found 2 bp (GT) insert between 31st and 32nd base upstream 5'-end of exon 4 (in intron 3) of PDE6B gene. There are novel complex heterozygous mutations of PDE6B gene responsible for a sporadic RP patient in China. This gene mutation associated with rod deterioration and RP. Several DNA variants were found in introns of PDE6B gene in national population.

Purpose This study was undertaken to identify causal mutations responsible for autosomal recessive retinitispigmentosa (arRP) in consanguineous families. Methods Large consanguineous families were ascertained from the Punjab province of Pakistan. An ophthalmic examination consisting of a fundus evaluation and electroretinography (ERG) was completed, and small aliquots of blood were collected from all participating individuals. Genomic DNA was extracted from white blood cells, and a genome-wide linkage or a locus-specific exclusion analysis was completed with polymorphic short tandem repeats (STRs). Two-point logarithm of odds (LOD) scores were calculated, and all coding exons and exon–intron boundaries of RP1 were sequenced to identify the causal mutation. Results The ophthalmic examination showed that affected individuals in all families manifest cardinal symptoms of RP. Genome-wide scans localized the disease phenotype to chromosome 8q, a region harboring RP1, a gene previously implicated in the pathogenesis of RP. Sanger sequencing identified a homozygous single base deletion in exon 4: c.3697delT (p.S1233Pfs22*), a single base substitution in intron 3: c.787+1G>A (p.I263Nfs8*), a 2 bp duplication in exon 2: c.551_552dupTA (p.Q185Yfs4*) and an 11,117 bp deletion that removes all three coding exons of RP1. These variations segregated with the disease phenotype within the respective families and were not present in ethnically matched control samples. Conclusions These results strongly suggest that these mutations in RP1 are responsible for the retinal phenotype in affected individuals of all four consanguineous families. PMID:27307693

Purpose Retinitispigmentosa (RP) is the most common retinal degeneration causing blindness. Although their clinical problems are amenable for the clinical diagnosis, their day-to-day problems for having to live with the disease are mostly unexplored. This study aims to explore and understand the issues and impact of people with RP on quality of life (QoL). Methods A qualitative research methodology to facilitate the understanding of the experiences of people with RP was carried out. Data were collected through audio-recorded semi-structured interviews. Thematic analysis occurred through the process of line-by-line coding, aggregation, and theme development using the NVivo-10 software. Results Twenty-three interviews were conducted (mean age=56 years; females, 14). We identified five major QoL themes: (1) struggle to perform important day-to-day tasks; (2) concerns about disease progression, disease outcome and personal safety; (3) facing a lot of emotional and psychological challenges; (4) experiencing a myriad of visual symptoms; and (5) adopting different strategies to cope and manage stressful circumstances. Difficulty in performing important day-to-day tasks was the most prominent QoL issue among these people. Their major concerns were going blind and uncertainties about their future. They face a lot of emotional and psychological challenges to adapt to the physiological stress associated with the progressive vision loss. However, they adopt several coping strategies to manage the stressful circumstances. Conclusions People with RP experience a myriad of QoL issues. Despite all the hardship, they remain optimistic and learn to accept their eye condition and move on in life. PMID:28085147

To report a novel mutation of the ABCC6 gene in a Japanese family that had a case of pseudoxanthoma elasticum (PXE) another with PXE and retinitispigmentosa. Ophthalmologic examinations were performed, and the ABCC6 gene was analysed by direct genomic sequencing. Fundus examinations of the 48-year-old proband disclosed angioid streaks and a peud'orange appearance of the retina of the both eyes, whereas both of his 25- and 20-year-old daughters had pigmentary degeneration and angioid streaks. In the sibilings, the mixed cone-rod ERG was almost nondetectable, whereas that of the proband was well-preserved. Molecular genetic analysis revealed that the proband has a homozygous nonsense mutation at the 595 bp in the ABCC6, and the siblings were heterozygous for the same mutation. This mutation was not detected in Japanese subjects in the JSNP database (http://snp.ims.u-tokyo.ac.jp/). Our results demonstrated an association between a novel mutation in the ABCC6 gene and PXE in a Japanese family.

The term retinitispigmentosa (RP) indicates a heterogeneous group of genetic rare ocular diseases in which either rods or cones are prevalently damaged. RP represents the most common hereditary cause of blindness in people from 20 to 60 years old. In general, the different RP forms consist of progressive photo-receptorial neuro-degenerations, which are characterized by variable visual disabilities and considerable socio-sanitary burden. Sometimes, RP patients do not become visually impaired or legally blind until their 40-50 years of age and/or maintain a quite acceptable sight for all their life. Other individuals with RP become completely blind very early or in middle childhood. Although there is no treatment that can effectively cure RP, in some case-series the disease’s progression seems to be reducible by specific preventive approaches. In the most part of RP patients, the quality of vision can be considerably increased by means of nanometer-controlled filters. In the present review, the main aspects of the routine clinical and rehabilitative managements for RP patients are described, particularly focusing on the importance of specific referral Centers to practice a real multidisciplinary governance of these dramatic diseases. PMID:22131870

Full Text Available OBJECTIVE: The purpose of this study was to investigate frequent disease-causing gene mutations in autosomal recessive retinitispigmentosa (arRP in the Japanese population. METHODS: In total, 99 Japanese patients with non-syndromic and unrelated arRP or sporadic RP (spRP were recruited in this study and ophthalmic examinations were conducted for the diagnosis of RP. Among these patients, whole exome sequencing analysis of 30 RP patients and direct sequencing screening of all CNGA1 exons of the other 69 RP patients were performed. RESULTS: Whole exome sequencing of 30 arRP/spRP patients identified disease-causing gene mutations of CNGA1 (four patients, EYS (three patients and SAG (one patient in eight patients and potential disease-causing gene variants of USH2A (two patients, EYS (one patient, TULP1 (one patient and C2orf71 (one patient in five patients. Screening of an additional 69 arRP/spRP patients for the CNGA1 gene mutation revealed one patient with a homozygous mutation. CONCLUSIONS: This is the first identification of CNGA1 mutations in arRP Japanese patients. The frequency of CNGA1 gene mutation was 5.1% (5/99 patients. CNGA1 mutations are one of the most frequent arRP-causing mutations in Japanese patients.

Full Text Available Macular corneal dystrophy (MCD is an autosomal recessive hereditary disease. In most cases, various mutations in carbohydrate sulfotransferase 6 (CHST6 gene are the main cause of MCD. These mutations lead to a defect in keratan sulfate synthesis. Retinitispigmentosa (RP is another eye disorder with nyctalopia as its common symptom. It has been shown that more than 65 genes have been implicated in different forms of RP. Herein, we report on a 9-member family with 2 girls and 5 boys. Both parents, one of the girls and one of the boys had normal eye vision and another boy had keratoconus. Other children (1 girl and 2 boys suffered from both MCD and RP. Corneal transplantation and medical supplements were used for MCD and RP during the follow-up period, respectively. Based on the family tree, it seems that the inheritance of both diseases is autosomal recessive. Based on our search of databases, there is no report on the simultaneous presence of MCD and RP. To the best of our knowledge, the present article is the first case report on this topic. Molecular genetic investigation is needed to clarify the mechanism of concurrent MCD and RP.

Purpose Using multiple imaging modalities we evaluated the changes in photoreceptor cells and RPE that are associated with bone spicule-shaped melanin pigmentation in retinitispigmentosa (RP). Methods In a cohort of 60 RP patients, short-wavelength autofluorescence (SW-AF), near-infrared (NIR)-AF, NIR-reflectance (NIR-R), spectral domain optical coherence tomography (SD-OCT) and color fundus images were studied. Results Central AF rings were visible in both SW-AF and NIR-AF images. Bone spicule pigmentation was non-reflective in NIR-R, hypoautofluorescent with SW-AF and NIR-AF imaging and presented as intraretinal hyperreflective foci in SD-OCT images. In areas beyond the AF ring outer border, the photoreceptor ellipsoid zone (EZ) band was absent in SD-OCT scans and the visibility of choroidal vessels in SW-AF, NIR-AF and NIR-R images was indicative of reduced RPE pigmentation. Choroidal visibility was most pronounced in the zone approaching peripheral areas of bone spicule pigmentation; here RPE/Bruch’s membrane thinning became apparent in SD-OCT scans. Conclusions These findings are consistent with a process by which RPE cells vacate their monolayer and migrate into inner retina in response to photoreceptor cell degeneration. The remaining RPE spread, undergo thinning and consequently become less pigmented. An explanation for the absence of NIR-AF melanin signal in relation to bone spicule pigmentation is not forthcoming. PMID:28005673

The Stiles-Crawford effect of the first kind is the retina's compensative response to loss of luminance efficiency for oblique stimulation manifested as the spot-size ratio departure from the perfect power coupling for a normal human eye. In a retinitispigmentosa eye (RP), the normal cone photoreceptor morphology is affected due to foveal cone loss and disrupted cone mosaic spatial arrangement with reduction in directional sensitivity. We show that the flattened Stiles-Crawford function (SCF) in a RP eye is due to a different spot-size ratio departure profile, that is, for the same loss of luminance efficiency, a RP eye has a smaller departure from perfect power coupling compared to a normal eye. Again, the difference in spot-size ratio departure increases from the centre towards the periphery, having zero value for axial entry and maximum value for maximum peripheral entry indicating dispersal of photoreceptor alignment which prevents the retina to go for a bigger compensative response as it lacks both in number and appropriate cone morphology to tackle the loss of luminance efficiency for oblique stimulation. The slope of departure profile also testifies to the flattened SCF for a RP eye. Moreover, the discrepancy in spot-size ratio departure between a normal and a RP eye is shown to have a direct bearing on the Stiles-Crawford diminution of visibility.

To identify USH2A mutations in Israeli patients with autosomal-recessive Usher syndrome type 2 (USH2) and retinitispigmentosa (RP). Patients from 95 families with RP and 4 with USH2 were clinically evaluated. USH2A exons 2-72 were scanned for mutations using single-strand conformation and sequencing analyses. The frequency of novel missense changes was determined in patients and controls using restriction endonucleases. The analysis revealed 3 USH2A mutations, 2 of which are novel, in 2 families with USH2 and a large family (MOL0051) with both USH2 and RP. Compound heterozygotes for 2 null mutations (Thr80fs and Arg737stop) in MOL0051 suffered from USH2 while compound heterozygotes for 1 of the null mutations and a novel missense mutation (Gly4674Arg) had nonsyndromic RP. Our results support the involvement of USH2A in nonsyndromic RP and we report here of a second, novel, missense mutation in this gene causing autosomal-recessive RP. Possible involvement of USH2A should be considered in the molecular genetic evaluation of patients with autosomal-recessive RP. Understanding the mechanism by which different USH2A mutations cause either USH2 or RP may assist in the development of novel therapeutic approaches.

I studied two genetic diseases, retinitispigmentosa (RP) and color vision anomaly, in Kamigoto, one of the off-shore islands in Nagasaki Prefecture. The Prevalance of RP patients in this island was estimated to be one in 473 persons. Among the RP patients observed, familial cases whose disorders are transmitted through successive generations comprised 25.7%. Although it seems that the inheritance mode of RP in these familial cases is autosomal dominant, an autosomal recessive fashion showing quasi-dominance cannot be ruled out, because inbreeding frequently occurs on this island. There were at least two types of RP, one with late onset (40 years of age or later) and the other with early onset, and patients with the latter RP tended to have a poor prognosis. Only a few RP patients had posterior subcapsular cataract, and none had pseudexfoliation in spite of advanced age. Color vision anomalies were found in 3.86% of high-school boys and in 0.41% of girls in this island, and they included protanopia (4.2%), protanomaly (10.4%), deuteranopia (37.5%), and deuteranomaly (47.9%). The prevalence in boys was comparable to that in the general Japanese population, but the prevalence in girls was higher in Kamigoto than in other districts. It is most likely that the unique findings regarding the two disorders reflect geographical and/or social features in Kamigoto island.

Retinitispigmentosa (RP) is a genetically heterogeneous disorder characterized by progressive loss of vision. The aim of this study was to identify the causative mutations in 272 Spanish families using a genotyping microarray. 272 unrelated Spanish families, 107 with autosomal recessive RP (arRP) and 165 with sporadic RP (sRP), were studied using the APEX genotyping microarray. The families were also classified by clinical criteria: 86 juveniles and 186 typical RP families. Haplotype and sequence analysis were performed to identify the second mutated allele. At least one-gene variant was found in 14% and 16% of the juvenile and typical RP groups respectively. Further study identified four new mutations, providing both causative changes in 11% of the families. Retinol Dehydrogenase 12 (RDH12) was the most frequently mutated gene in the juvenile RP group, and Usher Syndrome 2A (USH2A) and Ceramide Kinase-Like (CERKL) were the most frequently mutated genes in the typical RP group. The only variant found in CERKL was p.Arg257Stop, the most frequent mutation. The genotyping microarray combined with segregation and sequence analysis allowed us to identify the causative mutations in 11% of the families. Due to the low number of characterized families, this approach should be used in tandem with other techniques.

To determine the efficacy of sustained topical therapy with dorzolamide hydrochloride, 2%, on visual acuity and cystic macular lesions in patients with retinitispigmentosa and Usher syndrome. In a retrospective case series at a university hospital, 64 eyes of 32 patients with retinitispigmentosa or Usher syndrome receiving treatment with the topical dorzolamide formulation for 6 to 58 months were enrolled. Changes in visual acuity on the Early Treatment Diabetic Retinopathy Study chart and central foveal zone thickness on optical coherence tomography were measured during follow-up for the duration of treatment. Among the study cohort, 20 of 32 patients (63%) showed a positive response to treatment in at least 1 eye and 13 patients (41%) showed a positive response in both eyes. Four patients (20%) showed an initial response and a subsequent rebound of macular cysts. In 8 patients (25%), there was no response to treatment and the macular cysts worsened when compared with the pretreatment level. Ten patients (31%) had improvement in visual acuity by 7 or more letters in at least 1 eye at the most recent follow-up visit. Sixteen patients (67%) showed a reduction of more than 11% in the central foveal zone thickness in at least 1 eye when compared with the pretreatment level. Patients with either retinitispigmentosa or Usher syndrome who received treatment of cystoid macular edema with topical dorzolamide followed by an optical coherence tomography-guided strategy showed a decrease in central foveal zone thickness in most cases. Visual acuity improved in almost one-third of the cases, suggesting a potential corresponding visual benefit.

Vasoproliferative tumours may be primary or secondary and present with severe exudation leading to marked visual loss. We describe a 47-year-old man with unilateral secondary vasoproliferative tumour associated with sector retinitispigmentosa and Usher I syndrome who was successfully treated with a single session of photodynamic treatment. Standard treatment protocol was used except that the treatment duration was doubled. A year after the treatment, the angioma-like tumour vanished and exudation was dramatically reduced. Photodynamic therapy seems to be a minimally invasive and safe technique in eyes with secondary vasoproliferative tumours.

Purpose To determine the efficacy of multiple versions of a commercially available arrayed primer extension (APEX) microarray chip for autosomal recessive retinitispigmentosa (arRP). Methods We included 250 probands suspected of arRP who were genetically analyzed with the APEX microarray between January 2008 and November 2013. The mode of inheritance had to be autosomal recessive according to the pedigree (including isolated cases). If the microarray identified a heterozygous mutation, we performed Sanger sequencing of exons and exon–intron boundaries of that specific gene. The efficacy of this microarray chip with the additional Sanger sequencing approach was determined by the percentage of patients that received a molecular diagnosis. We also collected data from genetic tests other than the APEX analysis for arRP to provide a detailed description of the molecular diagnoses in our study cohort. Results The APEX microarray chip for arRP identified the molecular diagnosis in 21 (8.5%) of the patients in our cohort. Additional Sanger sequencing yielded a second mutation in 17 patients (6.8%), thereby establishing the molecular diagnosis. In total, 38 patients (15.2%) received a molecular diagnosis after analysis using the microarray and additional Sanger sequencing approach. Further genetic analyses after a negative result of the arRP microarray (n = 107) resulted in a molecular diagnosis of arRP (n = 23), autosomal dominant RP (n = 5), X-linked RP (n = 2), and choroideremia (n = 1). Conclusions The efficacy of the commercially available APEX microarray chips for arRP appears to be low, most likely caused by the limitations of this technique and the genetic and allelic heterogeneity of RP. Diagnostic yields up to 40% have been reported for next-generation sequencing (NGS) techniques that, as expected, thereby outperform targeted APEX analysis. PMID:25999674

Purpose The goal of this study was to identify mutations in X-chromosomal genes associated with retinitispigmentosa (RP) in patients from Germany, The Netherlands, Denmark, and Switzerland. Methods In addition to all coding exons of RP2, exons 1 through 15, 9a, ORF15, 15a and 15b of RPGR were screened for mutations. PCR products were amplified from genomic DNA extracted from blood samples and analyzed by direct sequencing. In one family with apparently dominant inheritance of RP, linkage analysis identified an interval on the X chromosome containing RPGR, and mutation screening revealed a pathogenic variant in this gene. Patients of this family were examined clinically and by X-inactivation studies. Results This study included 141 RP families with possible X-chromosomal inheritance. In total, we identified 46 families with pathogenic sequence alterations in RPGR and RP2, of which 17 mutations have not been described previously. Two of the novel mutations represent the most 3’-terminal pathogenic sequence variants in RPGR and RP2 reported to date. In exon ORF15 of RPGR, we found eight novel and 14 known mutations. All lead to a disruption of open reading frame. Of the families with suggested X-chromosomal inheritance, 35% showed mutations in ORF15. In addition, we found five novel mutations in other exons of RPGR and four in RP2. Deletions in ORF15 of RPGR were identified in three families in which female carriers showed variable manifestation of the phenotype. Furthermore, an ORF15 mutation was found in an RP patient who additionally carries a 6.4 kbp deletion downstream of the coding region of exon ORF15. We did not identify mutations in 39 sporadic male cases from Switzerland. Conclusions RPGR mutations were confirmed to be the most frequent cause of RP in families with an X-chromosomal inheritance pattern. We propose a screening strategy to provide molecular diagnostics in these families. PMID:18552978

To study whether the ERG and other clinical findings help to distinguish between advanced hydroxychloroquine (HCQ) retinopathy and pericentral or diffuse retinitispigmentosa (RP) with similar fundus appearance. We conducted a retrospective analysis of patients with advanced HCQ retinopathy (n = 11), pericentral RP (n = 8) and diffuse RP (n = 8). Pericentral RP was defined as having limited fundus damage and relatively normal flicker ERG time-to-peak. Diffuse RP had typical loss of the rod ERG and flicker timing delay. All patients showed reduced amplitude of the ISCEV responses in the full-field electroretinogram (ERG). Aspects of history, visual field results, fundus appearance, fundus autofluorescence and ocular coherence tomography were also compared. Relative to pericentral RP, patients with HCQ toxicity showed delayed flicker ERG time-to-peak and lower ERG amplitudes, particularly combined rod-cone responses. Relative to diffuse RP, most HCQ toxicity patients had some preserved rod ERG response, and there was no obvious predilection for rod over cone damage. In addition, patients with HCQ toxicity usually lacked markers of long-standing degeneration such as bone spicule figures or severe loss of peripheral field. History of familial disease and long-standing night blindness were specific to RP. While the early signs of HCQ damage are typically regional in the posterior pole, advanced disease is characteristically diffuse (unlike pericentral RP). This is appropriate for a systemic toxin, as is the finding that rods and cones were both affected in the ERG to a similar degree (unlike genetic rod-cone dystrophies). For patients with severe HCQ exposure and some of our discriminatory findings, and no family history or prior night blindness, HCQ toxicity is a sufficient diagnosis without invoking a second rare disease (Occam's razor).

To determine the refractive error in patients with autosomal recessive retinitispigmentosa (arRP) caused by RP1 mutations and to compare it with that of other genetic subtypes of RP. Twenty-six individuals had arRP with RP1 mutations, 25 had autosomal dominant RP (adRP) with RP1 mutation, 8 and 33 had X-linked RP (xlRP) with RP2 and RPGR mutations, respectively, 198 and 93 had Usher syndrome and arRP without RP1 mutations, respectively. The median of the spherical equivalent (SE) and the IQR (Q25-Q75) was determined and multiple comparisons were performed. arRP patients with RP1 mutations had SE median at -4.0 dioptres (D) OD (Ocula Dextra); -3.88 D OS (Ocula Sinistra), whereas arRP patients without RP1 mutations (-0.50 D OD; -0.75 D OS) and Usher syndrome patients (-0.50 D OD; -0.38 D OS) were significantly less myopic (pUsher syndrome and adRP with RP1 mutation had a narrow IQR (-9.06 to -1.13 D), whereas arRP with RP1 mutations and xlRP with RP2 or RPGR mutations had a larger range (-9.06; -1.13 D). arRP patients with RP1 mutations have myopia not different from patients with xlRP with RP2 or RPGR mutations, while RP patients from other genetic subgroups were emmetropic or mildly myopic. We suggest that arRP patients with high myopic refractive error should be preferentially analysed for RP1 mutations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

We aimed to identify novel genetic defects in the LCA5 gene underlying Leber congenital amaurosis (LCA) in the Spanish population and to describe the associated phenotype. Case series. A cohort of 217 unrelated Spanish families affected by autosomal recessive or isolated retinal dystrophy, that is, 79 families with LCA and 138 families with early-onset retinitispigmentosa (EORP). A total of 100 healthy, unrelated Spanish individuals were screened as controls. High-resolution homozygosity mapping was performed in 44 patients with LCA using genome-wide single nucleotide polymorphism (SNP) microarrays. Direct sequencing of the LCA5 gene was performed in 5 patients who showed homozygous regions at chromosome 6 and in 173 unrelated individuals with LCA or EORP. The ophthalmic history of 8 patients carrying LCA5 mutations was reviewed and additional examinations were performed, including electroretinography (ERG), optical coherence tomography (OCT), and fundus photography. Single nucleotide polymorphism genotyping, identity-by-descent (IBD) regions, LCA5 mutations, best-corrected visual acuity, visual field assessments, fundus appearance, ERG, and OCT findings. Four novel and 2 previously reported LCA5 mutations have been identified in 6 unrelated families with LCA by homozygosity mapping or Sanger sequencing. Thus, LCA5 mutations have a frequency of 7.6% in the Spanish population. However, no LCA5 mutations were found in 138 patients with EORP. Although most of the identified LCA5 mutations led to a truncated protein, a likely pathogenic missense variant was identified for the first time as a cause of LCA, segregating in 2 families. We also have characterized a novel splicing site mutation at the RNA level, demonstrating that the mutant LCA5 transcript was absent in a patient. All patients carrying LCA5 mutations presented nystagmus, night blindness, and progressive loss of visual acuity and visual field leading to blindness toward the third decade of life. Fundoscopy

RetinitisPigmentosa (RP) involves a group of genetically determined retinal diseases caused by a large number of mutations that result in rod photoreceptor cell death followed by gradual death of cone cells. Most cases of RP are monogenic, with more than 80 associated genes identified so far. The high number of genes and variants involved in RP, among other factors, is making the molecular characterization of RP a real challenge for many patients. Although HRM has been used for the analysis of isolated variants or single RP genes, as far as we are concerned, this is the first study that uses HRM analysis for a high-throughput screening of several RP genes. Our main goal was to test the suitability of HRM analysis as a genetic screening technique in RP, and to compare its performance with two of the most widely used NGS platforms, Illumina and PGM-Ion Torrent technologies. RP patients (n = 96) were clinically diagnosed at the Ophthalmology Department of Donostia University Hospital, Spain. We analyzed a total of 16 RP genes that meet the following inclusion criteria: 1) size: genes with transcripts of less than 4 kb; 2) number of exons: genes with up to 22 exons; and 3) prevalence: genes reported to account for, at least, 0.4% of total RP cases worldwide. For comparison purposes, RHO gene was also sequenced with Illumina (GAII; Illumina), Ion semiconductor technologies (PGM; Life Technologies) and Sanger sequencing (ABI 3130xl platform; Applied Biosystems). Detected variants were confirmed in all cases by Sanger sequencing and tested for co-segregation in the family of affected probands. We identified a total of 65 genetic variants, 15 of which (23%) were novel, in 49 out of 96 patients. Among them, 14 (4 novel) are probable disease-causing genetic variants in 7 RP genes, affecting 15 patients. Our HRM analysis-based study, proved to be a cost-effective and rapid method that provides an accurate identification of genetic RP variants. This approach is effective for

To investigate radial peripapillary capillary (RPC) network in patients affected by retinitispigmentosa (RP). Eleven patients (22 eyes) with previous diagnosis of RP and 16 age-matched healthy subjects (16 eyes) were enrolled. The diagnosis of RP was made based on both clinical features and electrophysiological examination. All patients underwent a complete ophthalmologic examination, including optical coherence tomography angiography and visual field (VF). The primary outcomes were the RPC vessel density in the peripapillary and disk areas; the secondary outcomes were the peripapillary retinal nerve fiber layer (RNFL) thickness and the mean defect at VF. A total of 19 eyes of 11 RP patients (5 males, 6 females) and 16 eyes of 16 healthy subjects (10 males, 6 females) were included for the analysis. RPC vessel density in the disk area was 46.5 ± 7.1% in the RP group and 45.4 ± 10.6% in the control group ( p = 0.754). RPC vessel density in the peripapillary area was significantly reduced in the RP group after the comparison with the control group (52.5 ± 5.0 and 57.2 ± 5.1%, respectively, p = 0.011). RNFL thickness was 85.9 ± 20.4 μm in the RP group and 104.0 ± 6.4 μm in the control group ( p = 0.002). RPC vessel density was significantly correlated with RNFL thickness values in RP patients, both in the disk and in the peripapillary area (Rho = 0.599 and p = 0.007 in the disk area, Rho = 0.665 and p = 0.002 in the peripapillary area, respectively). We showed that density of RPC is reduced in these patients in the peripapillary area. Moreover, the RPC vessel density correlates with the RNFL thickness.

Posterior column ataxia with retinitispigmentosa (PCARP) is an autosomal recessive disorder characterized by severe sensory ataxia, muscle weakness and atrophy, and progressive pigmentary retinopathy. Recently, mutations in the FLVCR1 gene were described in four families with this condition. We investigated the molecular basis and studied the phenotype of PCARP in a new family. The proband is a 33-year-old woman presented with sensory polyneuropathy and retinitispigmentosa (RP). The constellation of clinical findings with normal metabolic and genetic evaluation, including mitochondrial DNA (mtDNA) analysis and normal levels of phytanic acid and vitamin E, prompted us to seek other causes of our patient's condition. Sequencing of FLVCR1 in the proband and targeted mutation testing in her two affected siblings revealed two novel variants, c.1547G > A (p.R516Q) and c.1593+5_+8delGTAA predicted, respectively, to be highly conserved throughout evolution and affecting the normal splicing, therefore, deleterious. This study supports the pathogenic role of FLVCR1 in PCARP and expands the molecular and clinical spectra of PCARP. We show for the first time that nontransmembrane domain (TMD) mutations in the FLVCR1 can cause PCARP, suggesting different mechanisms for pathogenicity. Our clinical data reveal that impaired sensation can be part of the phenotypic spectrum of PCARP. This study along with previously reported cases suggests that targeted sequencing of the FLVCR1 gene should be considered in patients with severe sensory ataxia, RP, and peripheral sensory neuropathy.

To document the evolution and functional and structural significance of parafoveal rings of high-density fundus autofluorescence (AF) in patients with retinitispigmentosa and preserved visual acuity. Fifty-two patients with nonsyndromic retinitispigmentosa or Usher syndrome, who had a parafoveal ring of high-density AF and a visual acuity of 20/30 or better, were ascertained. All had international standard full-field electroretinography and pattern electroretinography. Autofluorescence imaging was repeated in 30 patients after periods of up to 9.3 years. Of the 52 patients, 35 underwent optical coherence tomography. Progressive constriction of the ring was detected in 17 patients. Ring radius reduced by up to 40% at a mean rate of between 0.8% and 15.8% per year. In 1 patient, a small ring was replaced by irregular AF; visual acuity deteriorated over the same period. There was a high correspondence between the lateral extent of the preserved optical coherence tomography inner segment/outer segment band and the diameter of the ring along the same optical coherence tomographic scan plane (slope, 0.9; r = 0.97; P retina and preserved photopic function. Serial fundus AF may provide prognostic indicators for preservation of central acuity and potentially assist in the identification and evaluation of patients suitable for treatment aimed at preservation of remaining function.

We describe a brother and sister with retinitispigmentosa (RP), growth failure, long eyelashes, and sparse hair. They were born to young healthy consanguineous parents and presented at birth with IUGR. Evolving pigmentary retinopathy was diagnosed at the age of 5 years. A similar condition (Oliver-McFarlane) syndrome was reported previously. Our two sibs confirm the existence of this autosomal recessive syndrome.

PURPOSE: To report changes in the tapetal-like reflex in a female carrier of RPGR ORF15 c.3395delA X-linked retinitispigmentosa (XLRP) between examinations at 16 and 22 years of age, and to report the observation that the tapetal-like reflex faded due to exposure to daylight and reappeared...

PURPOSE. To identify mutations in FAM161A underlying autosomal recessive retinitispigmentosa (arRP) in the Dutch and Belgian populations and to investigate whether common FAM161A-associated phenotypic features could be identified. METHODS. Homozygosity mapping, amplification-refractory mutation

Mutations in the ABCA4 gene have been associated with autosomal recessive Stargardt disease (STGD1), cone-rod dystrophy (CRD), and retinitispigmentosa (RP). We employed a recently developed genotyping microarray, the ABCR400-chip, to search for known ABCA4 mutations in patients with isolated or

PURPOSE: Defects in MAK, encoding a protein localized to the photoreceptor connecting cilium, have recently been associated with autosomal recessive retinitispigmentosa (RP). The aim of this study is to describe our detailed clinical observations in patients with MAK-associated RP, including an

In patients with autosomal-recessive retinitispigmentosa (arRP), homozygosity mapping was performed for detection of regions harboring genes that might be causative for RP. In one affected sib pair, a shared homozygous region of 5.0 Mb was identified on chromosome 6, within the RP25 locus. One of

Purpose Seven genes involved in precursor mRNA (pre-mRNA) splicing have been implicated in autosomal dominant retinitispigmentosa (adRP). We sought to detect mutations in all seven genes in Chinese families with RP, to characterize the relevant phenotypes, and to evaluate the prevalence of mutations in splicing genes in patients with adRP. Methods Six unrelated families from our adRP cohort (42 families) and two additional families with RP with uncertain inheritance mode were clinically characterized in the present study. Targeted sequence capture with next-generation massively parallel sequencing (NGS) was performed to screen mutations in 189 genes including all seven pre-mRNA splicing genes associated with adRP. Variants detected with NGS were filtered with bioinformatics analyses, validated with Sanger sequencing, and prioritized with pathogenicity analysis. Results Mutations in pre-mRNA splicing genes were identified in three individual families including one novel frameshift mutation in PRPF31 (p.Leu366fs*1) and two known mutations in SNRNP200 (p.Arg681His and p.Ser1087Leu). The patients carrying SNRNP200 p.R681H showed rapid disease progression, and the family carrying p.S1087L presented earlier onset ages and more severe phenotypes compared to another previously reported family with p.S1087L. In five other families, we identified mutations in other RP-related genes, including RP1 p. Ser781* (novel), RP2 p.Gln65* (novel) and p.Ile137del (novel), IMPDH1 p.Asp311Asn (recurrent), and RHO p.Pro347Leu (recurrent). Conclusions Mutations in splicing genes identified in the present and our previous study account for 9.5% in our adRP cohort, indicating the important role of pre-mRNA splicing deficiency in the etiology of adRP. Mutations in the same splicing gene, or even the same mutation, could correlate with different phenotypic severities, complicating the genotype–phenotype correlation and clinical prognosis. PMID:24940031

Full Text Available Retinitispigmentosa (RP is a heterogeneous group of progressive retinal degenerations characterized by pigmentation and atrophy in the mid-periphery of the retina. Twenty two subjects from a four-generation Chinese family with RP and thin cornea, congenital cataract and high myopia is reported in this study. All family members underwent complete ophthalmologic examinations. Patients of the family presented with bone spicule-shaped pigment deposits in retina, retinal vascular attenuation, retinal and choroidal dystrophy, as well as punctate opacity of the lens, reduced cornea thickness and high myopia. Peripheral venous blood was obtained from all patients and their family members for genetic analysis. After mutation analysis in a few known RP candidate genes, exome sequencing was used to analyze the exomes of 3 patients III2, III4, III6 and the unaffected mother II2. A total of 34,693 variations shared by 3 patients were subjected to several filtering steps against existing variation databases. Identified variations were verified in the rest family members by PCR and Sanger sequencing. Compound heterozygous c.802-8_810del17insGC and c.1091-2A>G mutations of the CYP4V2 gene, known as genetic defects for Bietti crystalline corneoretinal dystrophy, were identified as causative mutations for RP of this family.

This study aimed to identify the genetics underlying dominant forms of inherited retinal dystrophies using whole exome sequencing (WES) in six families extensively screened for known mutations or genes. Thirty-eight individuals were subjected to WES. Causative variants were searched among single nucleotide variants (SNVs) and insertion/deletion variants (indels) and whenever no potential candidate emerged, copy number variant (CNV) analysis was performed. Variants or regions harboring a candidate variant were prioritized and segregation of the variant with the disease was further assessed using Sanger sequencing in case of SNVs and indels, and quantitative PCR (qPCR) for CNVs. SNV and indel analysis led to the identification of a previously reported mutation in PRPH2. Two additional mutations linked to different forms of retinal dystrophies were identified in two families: a known frameshift deletion in RPGR, a gene responsible for X-linked retinitispigmentosa and p.Ser163Arg in C1QTNF5 associated with Late-Onset Retinal Degeneration. A novel heterozygous deletion spanning the entire region of PRPF31 was also identified in the affected members of a fourth family, which was confirmed with qPCR. This study allowed the identification of the genetic cause of the retinal dystrophy and the establishment of a correct diagnosis in four families, including a large heterozygous deletion in PRPF31, typically considered one of the pitfalls of this method. Since all findings in this study are restricted to known genes, we propose that targeted sequencing using gene-panel is an optimal first approach for the genetic screening and that once known genetic causes are ruled out, WES might be used to uncover new genes involved in inherited retinal dystrophies. PMID:26197217

Purpose To study the phenotype in two families with genetically identified autosomal dominant retinitispigmentosa (adRP) focusing on macular structure and function. Methods Clinical data were collected at the Department of Ophthalmology, Lund University, Sweden, for affected and unaffected family members from two pedigrees with adRP. Examinations included optical coherence tomography (OCT), full-field electroretinography (ffERG), and multifocal electroretinography (mfERG). Molecular genetic screening was performed for known mutations associated with adRP. Results The mode of inheritance was autosomal dominant in both families. The members of the family with a mutation in the PRPF31 (p.IVS6+1G>T) gene had clinical features characteristic of RP, with severely reduced retinal rod and cone function. The degree of deterioration correlated well with increasing age. The mfERG showed only centrally preserved macular function that correlated well with retinal thinning on OCT. The family with a mutation in the RHO (p.R135W) gene had an extreme intrafamilial variability of the phenotype, with more severe disease in the younger generations. OCT showed pathology, but the degree of morphological changes was not correlated with age or with the mfERG results. The mother, with a de novo mutation in the RHO (p.R135W) gene, had a normal ffERG, and her retinal degeneration was detected merely with the reduced mfERG. Conclusions These two families demonstrate the extreme inter- and intrafamilial variability in the clinical phenotype of adRP. This is the first Swedish report of the clinical phenotype associated with a mutation in the PRPF31 (p.IVS6+1G>T) gene. Our results indicate that methods for assessment of the central retinal structure and function may improve the detection and characterization of the RP phenotype. PMID:27212874

Objective. The prospective efficacy of peripheral retinal prostheses for guiding orientation and mobility in the absence of residual vision, as compared to an implant for the central visual field (VF), was evaluated using simulated prosthetic vision (SPV). Approach. Sighted volunteers wearing a head-mounted display performed an obstacle circumvention task under SPV. Mobility and orientation performance with three layouts of prosthetic vision were compared: peripheral prosthetic vision of higher visual acuity (VA) but limited VF, of wider VF but limited VA, as well as centrally restricted prosthetic vision. Learning curves using these layouts were compared fitting an exponential model to the mobility and orientation measures. Main results. Using peripheral layouts, performance was superior to the central layout. Walking speed with both higher-acuity and wider-angle layouts was 5.6% higher, and mobility errors reduced by 46.4% and 48.6%, respectively, as compared to the central layout. The wider-angle layout yielded the least number of collisions, 63% less than the higher-acuity and 73% less than the central layout. Using peripheral layouts, the number of visual-scanning related head movements was 54.3% (higher-acuity) and 60.7% (wider-angle) lower, as compared to the central layout, and the ratio of time standing versus time walking was 51.9% and 61.5% lower, respectively. Learning curves did not differ between layouts, except for time standing versus time walking, where both peripheral layouts achieved significantly lower asymptotic values compared to the central layout. Significance. Beyond complementing residual vision for an improved performance, peripheral prosthetic vision can effectively guide mobility in the later stages of retinitispigmentosa (RP) without residual vision. Further, the temporal dynamics of learning peripheral and central prosthetic vision are similar. Therefore, development of a peripheral retinal prosthesis and early implantation to

Full Text Available AIM: To screen mutations in the retinitispigmentosa 1 (RP1 gene and the rhodopsin (RHO gene in Chinese patients with retinitispigmentosa sine pigmento (RPSP and describe the genotype-phenotype relationship of the mutations.METHODS:Twenty affected, unrelated Chinese individuals with RPSP (4 autosomal dominant RPSP, 12 autosomal recessive RPSP and 4 unknown inheritance pattern were recruited between 2009 and 2012. The clinical features were determined by complete ophthalmologic examinations. Polymerase chain reaction (PCR and direct DNA sequencing were used to screen the entire coding region and splice junctions of the RP1 gene and the RHO gene. The cosegregation analysis and population frequency studies were performed for patients with identified mutations.RESULTS: Five variants in the RP1 gene and one in the RHO gene were detected in 20 probands. Four missense changes (rs444772, rs446227, rs414352, rs441800 and one non-coding variant (rs56340615 were common SNPs and none of them showed a significant relationship with RPSP. A missense mutation p.R1443W was identified in the RP1 gene in three affected individuals from a family with autosomal dominant RPSP and was found to cosegregate with the phenotype in this family, suggestive of pathogenic. In addition, population frequency analysis showed the p.R1443W mutation was absent in 300 healthy controls.CONCLUSION: The identification of p.R1443W mutation cosegregating in a family with autosomal dominant RPSP highlights an atypical phenotype of the RP1 gene mutation, while RHO gene is not associated with the pathogenesis of RPSP in this study. To our knowledge, this is the fist mutation identified to associate with RPSP.

To screen mutations in the retinitispigmentosa 1 (RP1) gene and the rhodopsin (RHO) gene in Chinese patients with retinitispigmentosa sine pigmento (RPSP) and describe the genotype-phenotype relationship of the mutations. Twenty affected, unrelated Chinese individuals with RPSP (4 autosomal dominant RPSP, 12 autosomal recessive RPSP and 4 unknown inheritance pattern) were recruited between 2009 and 2012. The clinical features were determined by complete ophthalmologic examinations. Polymerase chain reaction (PCR) and direct DNA sequencing were used to screen the entire coding region and splice junctions of the RP1 gene and the RHO gene. The cosegregation analysis and population frequency studies were performed for patients with identified mutations. Five variants in the RP1 gene and one in the RHO gene were detected in 20 probands. Four missense changes (rs444772, rs446227, rs414352, rs441800) and one non-coding variant (rs56340615) were common SNPs and none of them showed a significant relationship with RPSP. A missense mutation p.R1443W was identified in the RP1 gene in three affected individuals from a family with autosomal dominant RPSP and was found to cosegregate with the phenotype in this family, suggestive of pathogenic. In addition, population frequency analysis showed the p.R1443W mutation was absent in 300 healthy controls. The identification of p.R1443W mutation cosegregating in a family with autosomal dominant RPSP highlights an atypical phenotype of the RP1 gene mutation, while RHO gene is not associated with the pathogenesis of RPSP in this study. To our knowledge, this is the fist mutation identified to associate with RPSP.

To detect the disease-causing genes of 10 retinitispigmentosa pedigrees by using exon combined target region capture sequencing chip. Pedigree investigation study. From October 2010 to December 2013, 10 RP pedigrees were recruited for this study in Ningxia Eye Hospital. All the patients and family members received complete ophthalmic examinations. DNA was abstracted from patients, family members and controls. Using exon combined target region capture sequencing chip to screen the candidate disease-causing mutations. Polymerase chain reaction (PCR) and direct sequencing were used to confirm the disease-causing mutations. Seventy patients and 23 normal family members were recruited from 10 pedigrees. Among 10 RP pedigrees, 1 was autosomal dominant pedigrees and 9 were autosomal recessive pedigrees. 7 mutations related to 5 genes of 5 pedigrees were detected. A frameshift mutation on BBS7 gene was detected in No.2 pedigree, the patients of this pedigree combined with central obesity, polydactyly and mental handicap. No.2 pedigree was diagnosed as Bardet-Biedl syndrome finally. A missense mutation was detected in No.7 and No.10 pedigrees respectively. Because the patients suffered deafness meanwhile, the final diagnosis was Usher syndrome. A missense mutation on C3 gene related to age-related macular degeneration was also detected in No. 7 pedigrees. A nonsense mutation and a missense mutation on CRB1 gene were detected in No. 1 pedigree and a splicesite mutation on PROM1 gene was detected in No. 5 pedigree. Retinitispigmentosa is a kind of genetic eye disease with diversity clinical phenotypes. Rapid and effective genetic diagnosis technology combined with clinical characteristics analysis is helpful to improve the level of clinical diagnosis of RP.

Aim To report photographically the evolution of an astrocytic hamartoma of the left optic nerve head over a 2-year follow-up in a patient with retinitispigmentosa. Methods A 14-year-old boy was seen in the medical retina clinic with a 3-year history of night blindness. Best corrected visual acuity was 6/18 in both eyes. Colour vision was normal in both eyes and confrontation fields showed peripheral constriction. Fundus examination revealed bone spicule pigmentary changes at the retinal mid periphery typical of retinitispigmentosa and superficial globules at the margins of both optic nerve heads. Electrodiagnostic tests confirmed moderately severe rod cone dystrophy with macular involvement bilaterally. Results Two years later, the ocular examination was unchanged except for the appearance of the optic nerve head lesion in the left eye. There was an increase in the size of the lesion which was diagnosed as an astrocytic hamartoma. Further investigations were recommended to exclude neurofibromatosis and tuberous sclerosis. Conclusion Astrocytic hamartomas of the optic nerve head and optic nerve head drusen have both been described in patients with retinitispigmentosa. They can be a diagnostic dilemma although drusen are more common (10%). To differentiate these two entities it is very important to document any growth during the follow-up period which is suggestive of astrocytic hamartoma rather than optic disc drusen. PMID:21347192

To report photographically the evolution of an astrocytic hamartoma of the left optic nerve head over a 2-year follow-up in a patient with retinitispigmentosa. A 14-year-old boy was seen in the medical retina clinic with a 3-year history of night blindness. Best corrected visual acuity was 6/18 in both eyes. Colour vision was normal in both eyes and confrontation fields showed peripheral constriction. Fundus examination revealed bone spicule pigmentary changes at the retinal mid periphery typical of retinitispigmentosa and superficial globules at the margins of both optic nerve heads. Electrodiagnostic tests confirmed moderately severe rod cone dystrophy with macular involvement bilaterally. Two years later, the ocular examination was unchanged except for the appearance of the optic nerve head lesion in the left eye. There was an increase in the size of the lesion which was diagnosed as an astrocytic hamartoma. Further investigations were recommended to exclude neurofibromatosis and tuberous sclerosis. Astrocytic hamartomas of the optic nerve head and optic nerve head drusen have both been described in patients with retinitispigmentosa. They can be a diagnostic dilemma although drusen are more common (10%). To differentiate these two entities it is very important to document any growth during the follow-up period which is suggestive of astrocytic hamartoma rather than optic disc drusen.

The aim of this study was to describe a new pathogenic variant in the mutational hot spot exon ORF15 of retinitispigmentosa GTPase regulator (RPGR) gene within an Italian family with X-linked retinitispigmentosa (RP), detailing its distinctive genotype-phenotype correlation with pathologic myopia (PM). All members of this RP-PM family underwent a complete ophthalmic examination. The entire open reading frames of RPGR and retinitispigmentosa 2 genes were analyzed by Sanger sequencing. A novel frame-shift mutation in exon ORF15 of RPGR gene (c.2091_2092insA; p.A697fs) was identified as hemizygous variant in the male proband with RP, and as heterozygous variant in the females of this pedigree who invariably exhibited symmetrical PM in both eyes. The c.2091_2092insA mutation coherently co-segregated with the observed phenotypes. These findings expand the spectrum of X-linked RP variants. Interestingly, focusing on Caucasian ethnicity, just three RPGR mutations are hitherto reported in RP-PM families: one of these is located in exon ORF15, but none appears to be characterized by a high penetrance of PM trait as observed in the present, relatively small, pedigree. The geno-phenotypic attributes of this heterozygosity suggest that gain-of-function mechanism could give rise to PM via a degenerative cell-cell remodeling of the retinal structures. PMID:27995965

Full Text Available Aim: To report photographically the evolution of an astrocytic hamartoma of the left optic nerve head over a 2-year follow-up in a patient with retinitispigmentosa. Methods: A 14-year-old boy was seen in the medical retina clinic with a 3-year history of night blindness. Best corrected visual acuity was 6/18 in both eyes. Colour vision was normal in both eyes and confrontation fields showed peripheral constriction. Fundus examination revealed bone spicule pigmentary changes at the retinal mid periphery typical of retinitispigmentosa and superficial globules at the margins of both optic nerve heads. Electrodiagnostic tests confirmed moderately severe rod cone dystrophy with macular involvement bilaterally. Results: Two years later, the ocular examination was unchanged except for the appearance of the optic nerve head lesion in the left eye. There was an increase in the size of the lesion which was diagnosed as an astrocytic hamartoma. Further investigations were recommended to exclude neurofibromatosis and tuberous sclerosis. Conclusion: Astrocytic hamartomas of the optic nerve head and optic nerve head drusen have both been described in patients with retinitispigmentosa. They can be a diagnostic dilemma although drusen are more common (10%. To differentiate these two entities it is very important to document any growth during the follow-up period which is suggestive of astrocytic hamartoma rather than optic disc drusen.

PURPOSE To test the hypothesis that the evaluation of retinal structure can have diagnostic value in differentiating between incomplete congenital stationary night blindness (CSNB2) and retinitispigmentosa (RP). To compare retinal thickness differences between patients with CSNB2 and myopic controls. DESIGN Prospective cross-sectional study. METHODS Ten eyes of 5 patients diagnosed with CSNB2 (4 X-linked recessive, 1 autosomal recessive) and 6 eyes of 3 patients with RP (2 autosomal dominant, 1 autosomal recessive) were evaluated with spectral-domain optical coherence tomography (SD OCT) and fundus autofluorescence (FAF). Diagnoses of CSNB2 and RP were confirmed by full-field electroretinography (ERG). Manual segmentation of retinal layers, aided by a computer program, was performed by 2 professional segmenters on SD OCT images of all CSNB2 patients and 4 age-similar, normal myopic controls. Seven patients were screened for mutations with congenital stationary night blindness and RP genotyping arrays. RESULTS Patients with CSNB2 had specific findings on SD OCT and FAF that were distinct from those found in RP. CSNB2 patients showed qualitatively normal SD OCT results with preserved photoreceptor inner segment/outer segment junction, whereas this junction was lost in RP patients. In addition, CSNB2 patients had normal FAF images, whereas patients with RP demonstrated a ring of increased autofluorescence around the macula. On SD OCT segmentation, the inner and outer retinal layers of both X-linked recessive and autosomal recessive CSNB2 patients were thinner compared with those of normal myopic controls, with means generally outside of normal 95% confidence intervals. The only layers that demonstrated similar thickness between CSNB2 patients and the controls were the retinal nerve fiber layer and, temporal to the fovea, the combined outer segment layer and retinal pigment epithelium. A proband and his 2 affected brothers from a family segregating X-linked recessive

Retinitispigmentosa is the most frequent group of inherited retinal dystrophies. It is highly heterogeneous, with more than 80 disease-causing genes 27 of which are known to cause autosomal dominant RP (adRP), having been identified. In this study a total of 29 index cases were ascertained based on a family tree compatible with adRP. A custom panel of 31 adRP genes was analysed by targeted next-generation sequencing using the Ion PGM platform in combination with Sanger sequencing. This allowed us to detect putative disease-causing mutations in 14 out of the 29 (48.28%) families analysed. Remarkably, around 38% of all adRP cases analysed showed mutations affecting the splicing process, mainly due to mutations in genes coding for spliceosome factors (SNRNP200 and PRPF8) but also due to splice-site mutations in RHO. Twelve of the 14 mutations found had been reported previously and two were novel mutations found in PRPF8 in two unrelated patients. In conclusion, our results will lead to more accurate genetic counselling and will contribute to a better characterisation of the disease. In addition, they may have a therapeutic impact in the future given the large number of studies currently underway based on targeted RNA splicing for therapeutic purposes. PMID:28045043

Full Text Available AIM: To make comprehensive molecular diagnosis for retinitispigmentosa (RP patients in a consanguineous Han Chinese family using next generation sequencing based Capture-NGS screen technology. METHODS: A five-generation Han Chinese family diagnosed as non-syndromic X-linked recessive RP (XLRP was recruited, including four affected males, four obligate female carriers and eleven unaffected family members. Capture-NGS was performed using a custom designed capture panel covers 163 known retinal disease genes including 47 RP genes, followed by the validation of detected mutation using Sanger sequencing in all recruited family members. RESULTS: Capture-NGS in one affected 47-year-old male reveals a novel mutation, c.2417_2418insG:p.E806fs, in exon ORF15 of RP GTPase regulator (RPGR gene results in a frameshift change that results in a premature stop codon and a truncated protein product. The mutation was further validated in three of four affected males and two of four female carriers but not in the other unaffected family members. CONCLUSION: We have identified a novel mutation, c.2417_2418insG:p.E806fs, in a Han Chinese family with XLRP. Our findings expand the mutation spectrum of RPGR and the phenotypic spectrum of XLRP in Han Chinese families, and confirms Capture-NGS could be an effective and economic approach for the comprehensive molecular diagnosis of RP.

Full Text Available Aims. Several treatments have been proposed to slow down progression of Retinitispigmentosa (RP, a hereditary retinal degenerative condition leading to severe visual impairment. The aim of this study is to systematically review data from randomized clinical trials (RCTs evaluating safety and efficacy of medical interventions for the treatment of RP. Methods. Randomized clinical trials on medical treatments for syndromic and nonsyndromic RP published up to December 2014 were included in the review. Visual acuity, visual field, electroretinogram, and adverse events were used as outcome measures. Results. The 19 RCTs included in this systematic review included trials on hyperbaric oxygen delivery, topical brimonidine tartrate, vitamins, docosahexaenoic acid, gangliosides, lutein, oral nilvadipine, ciliary neurotrophic factor, and valproic acid. All treatments proved safe but did not show significant benefit on visual function. Long term supplementation with vitamin A showed a significantly slower decline rate in electroretinogram amplitude. Conclusions. Although all medical treatments for RP appear safe, evidence emerging from RCTs is limited since they do not present comparable results suitable for quantitative statistical analysis. The limited number of RCTs, the poor clinical results, and the heterogeneity among studies negatively influence the strength of recommendations for the long term management of RP patients.

Abstract Background Single-gene disorders related to ischemic stroke seem to be an important cause of stroke in young patients without known risk factors. To identify new genes responsible of such diseases, we studied a consanguineous Moroccan family with three affected individuals displaying hereditary leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitispigmentosa that appears to segregate in autosomal recessive pattern. Methods All family members underwent neurologic...

Usher syndrome (USH) is the most prevalent cause of hereditary deafness-blindness in humans. In this review, we pinpoint new insights regarding the molecular mechanisms defective in this syndrome, its molecular diagnosis and prospective therapies. Animal models wherein USH proteins were targeted at different maturation stages of the auditory hair cells have been engineered, shedding new light on the development and functioning of the hair bundle, the sound receptive structure. Improved protocols and guidelines for early molecular diagnosis of USH (USH genotyping microarrays, otochips and complete Sanger sequencing of the 366 coding exons of identified USH genes) have been developed. Approaches to alleviate or cure hearing and visual impairments have been initiated, leading to various degrees of functional rescuing. Whereas the mechanisms underlying hearing impairment in USH patients are being unraveled, showing in particular that USH1 proteins are involved in the shaping of the hair bundle and the functioning of the mechanoelectrical transduction machinery, the mechanisms underlying the retinal defects are still unclear. Efforts to improve clinical diagnosis have been successful. Yet, despite some encouraging results, further development of therapeutic approaches is necessary to ultimately treat this dual sensory defect.

Purpose To evaluate the long-term efficacy of ciliary neurotrophic factor delivered via an intraocular encapsulated cell implant for the treatment of retinitispigmentosa (RP). Design Long-term follow up of a multicenter, sham-controlled study. Methods Thirty-six patients at three CNTF4 sites were randomly assigned to receive a high- or low- dose implant in one eye and sham surgery in the fellow eye. The primary endpoint (change in visual field sensitivity at 12 months) has been reported previously.1 Here we report long-term visual acuity, visual field and optical coherence tomography (OCT) outcomes in 24 patients either retaining or explanting the device at 24 months relative to sham-treated eyes. Results Eyes retaining the implant showed significantly greater visual field loss from baseline than either explanted eyes or sham eyes through 42 months. By 60 months and continuing through 96 months, visual field loss was comparable among sham-treated eyes, eyes retaining the implant and explanted eyes, as was visual acuity and OCT macular volume. Conclusions Over the short term, ciliary neurotrophic factor released continuously from an intra-vitreal implant lead to loss of total visual field sensitivity that was greater than the natural progression in the sham-treated eye. This additional loss of sensitivity related to the active implant was reversible when the implant was removed. Over the long term (60 – 96 months), there was no evidence of efficacy for visual acuity, visual field sensitivity or OCT measures of retinal structure. PMID:27457255

PAP-1 is an in vitro phosphorylation target of the Pim-1 oncogene. Although PAP-1 binds to Pim-1, it is not a substrate for phosphorylation by Pim-1 in vivo. PAP-1 has recently been implicated as the defective gene in RP9, one type of autosomal dominant retinitispigmentosa (adRP). However, RP9 is a rare disease and only two missense mutations have been described, so the report of a link between PAP-1 and RP9 was tentative. The precise cellular role of PAP-1 was also unknown at that time. We now report that PAP-1 localizes in nuclear speckles containing the splicing factor SC35 and interacts directly with another splicing factor, U2AF35. Furthermore, we used in vitro and in vivo splicing assays to show that PAP-1 has an activity, which alters the pattern of pre-mRNA splicing and that this activity is dependent on the phosphorylation state of PAP-1. We used the same splicing assay to examine the activities of two mutant forms of PAP-1 found in RP9 patients. The results showed that while one of the mutations, H137L, had no effect on splicing activity compared with that of wild-type PAP-1, the other, D170G, resulted in both a defect in splicing activity and a decreased proportion of phosphorylated PAP-1. The D170G mutation may therefore cause RP by altering splicing of retinal genes through a decrease in PAP-1 phosphorylation. These results demonstrate that PAP-1 has a role in pre-mRNA splicing and, given that three other splicing factors have been implicated in adRP, this finding provides compelling further evidence that PAP-1 is indeed the RP9 gene

Objective. The prospective efficacy of a future peripheral retinal prosthesis complementing residual vision to raise mobility performance in non-end stage retinitispigmentosa (RP) was evaluated using simulated prosthetic vision (SPV). Approach. Normally sighted volunteers were fitted with a wide-angle head-mounted display and carried out mobility tasks in photorealistic virtual pedestrian scenarios. Circumvention of low-lying obstacles, path following, and navigating around static and moving pedestrians were performed either with central simulated residual vision of 10° alone or enhanced by assistive SPV in the lower and lateral peripheral visual field (VF). Three layouts of assistive vision corresponding to hypothetical electrode array layouts were compared, emphasizing higher visual acuity, a wider visual angle, or eccentricity-dependent acuity across an intermediate angle. Movement speed, task time, distance walked and collisions with the environment were analysed as performance measures. Main results. Circumvention of low-lying obstacles was improved with all tested configurations of assistive SPV. Higher-acuity assistive vision allowed for greatest improvement in walking speeds—14% above that of plain residual vision, while only wide-angle and eccentricity-dependent vision significantly reduced the number of collisions—both by 21%. Navigating around pedestrians, there were significant reductions in collisions with static pedestrians by 33% and task time by 7.7% with the higher-acuity layout. Following a path, higher-acuity assistive vision increased walking speed by 9%, and decreased collisions with stationary cars by 18%. Significance. The ability of assistive peripheral prosthetic vision to improve mobility performance in persons with constricted VFs has been demonstrated. In a prospective peripheral visual prosthesis, electrode array designs need to be carefully tailored to the scope of tasks in which a device aims to assist. We posit that maximum

Full Text Available Purpose. To investigate genetic and clinical features of patients with rhodopsin (RHO mutations in two Japanese families with autosomal dominant retinitispigmentosa (adRP. Methods. Whole-exome sequence analysis was performed in ten adRP families. Identified RHO mutations for the cosegregation analysis were confirmed by Sanger sequencing. Ophthalmic examinations were performed to evaluate the RP phenotypes. The impact of the RHO mutation on the rhodopsin conformation was examined by molecular modeling analysis. Results. In two adRP families, we identified two RHO mutations (c.377G>T (p.W126L and c.1036G>C (p.A346P, one of which was novel. Complete cosegregation was confirmed for each mutation exhibiting the RP phenotype in both families. Molecular modeling predicted that the novel mutation (p.W126L might impair rhodopsin function by affecting its conformational transition in the light-adapted form. Clinical phenotypes showed that patients with p.W126L exhibited sector RP, whereas patients with p.A346P exhibited classic RP. Conclusions. Our findings demonstrated that the novel mutation (p.W126L may be associated with the phenotype of sector RP. Identification of RHO mutations is a very useful tool for predicting disease severity and providing precise genetic counseling.

EYS and USH2A are the most common causative genes for retinitispigmentosa (RP) in Japan. We determined the clinical outcomes for USH2A-related non-syndromic RP or Usher syndrome type II (USH2). Two non-syndromic RP and 11 USH2 patients with previously identified USH2A mutations were included. Their complete history and medical records were collected using standard procedures. Visual fields and acuity were compared with those of patients with EYS mutations. Clinical analyses were based on ophthalmic and otolaryngologic examinations. In all patients, the fundus displayed changes typical of RP. Most patients showed relatively well-preserved visual acuity in their thirties or forties, with rapid deterioration in their fifties. Concentric constriction started in the twenties or thirties, and no effective residual visual field was observed after the fifties. The visual outcome for non-syndromic RP or USH2 patients with USH2A mutations is consistent with that for RP patients with EYS mutations.

Technological advances present an opportunity for more people with, or at risk of, developing retinitispigmentosa (RP) to be offered genetic testing. Valuation of these tests using current evaluative frameworks is problematic since benefits may be derived from diagnostic information rather than improvements in health. This pilot study aimed to explore if contingent valuation method (CVM) can be used to value the benefits of genetic testing for RP. CVM was used to elicit willingness-to-pay (WTP) values for (1) genetic counselling and (2) genetic counselling with genetic testing. Telephone and face-to-face interviews with a purposive sample of individuals with (n=25), and without (n=27), prior experience of RP were used to explore the feasibility and validity of CVM in this context. Faced with a hypothetical scenario, the majority of participants stated that they would seek genetic counselling and testing in the context of RP. Between participant groups, respondents offered similar justifications for stated WTP values. Overall stated WTP was higher for genetic counselling plus testing (median=£524.00) compared with counselling alone (median=£224.50). Between-group differences in stated WTP were statistically significant; participants with prior knowledge of the condition were willing to pay more for genetic ophthalmology services. Participants were able to attach a monetary value to the perceived potential benefit that genetic testing offered regardless of prior experience of the condition. This exploratory work represents an important step towards evaluating these services using formal cost-benefit analysis.

Nonsyndromic retinitispigmentosa (RP) is the most common inherited retinal degeneration, and prevalence of the disease has been reported in populations of American and European origin with a relatively low consanguinity rate. Our aim was to determine the prevalence of nonsyndromic RP in the Jerusalem region, which has a population of about 1 million individuals with a high rate of consanguinity. The patients' clinical data included eye exam findings (visual acuity, anterior segment, and funduscopy) as well as electroretinographic (ERG) testing results under scotopic and photopic conditions. Mutation analysis on a subgroup of patients was performed mainly with candidate gene analysis and homozygosity mapping. We evaluated the medical records of patients with degenerative retinal diseases residing in the Jerusalem region who were examined over the past 20 years in a large tertiary medical center. A total of 453 individuals affected with nonsyndromic RP were diagnosed at our center, according to funduscopic findings and ERG testing. Based on the estimated population size of 945,000 individuals who reside in the vicinity of Jerusalem, the prevalence of nonsyndromic RP in this region is 1:2,086. The prevalence of RP was higher among Arab Muslims (1:1,798) compared to Jews (1:2,230), mainly due to consanguineous marriages that are more common in the Arab Muslim population. To identify the genetic causes of RP in our cohort, we recruited 383 patients from 183 different families for genetic analysis: 70 with autosomal recessive (AR) inheritance, 15 with autosomal dominant, 86 isolate cases, and 12 with an X-linked inheritance pattern. In 64 (35%) of the families, we identified the genetic cause of the disease, and we revised the inheritance pattern of 20 isolate cases to the AR pattern; 49% of the families in our cohort had AR inheritance. Interestingly, in 42 (66%) of the genetically identified families, the cause of disease was a founder mutation. Previous studies

Tissues of the auditory, ocular and reproductive systems have some similarities in their protein families and structures. Consequently, syndromes comprising these systems are described. Hearing loss alone is a component of more than 400 known syndromes and is a common nonsyndromic congenital disorder. Here we describe a syndrome in five brothers with the distinctive presentation of late-onset progressive hearing loss, cataracts, retinitispigmentosa, sperm motility and shape problems in a family from the Kurdish population in Iran. The clinical findings of these patients are presented in detail and compared to the classical Usher syndromes. (c) 2007 Wiley-Liss, Inc

Full Text Available Os autores apresentam dois casos de vasculopatia retiniana tipo Coats associada a retinose pigmentar. Estes são os primeiros casos entre irmãos descritos no Brasil e nosso objetivo é anexar mais 2 casos, aos 47 descritos na literatura mundial.The authors presents two cases of Coats' type exsudative vasculopathy associated with retinitispigmentosa. These are the first cases in siblings described in Brazil and our purpose is to add two more cases, to the 47 described in the world literature.

Usher syndrome is a frequent cause of the combination of deafness and blindness due to retinitispigmentosa (RP). Five genes are known to underlie different forms of Usher syndrome type I (USH1). In the Ashkenazi Jewish population, the R245X mutation of the PCDH15 gene may be the most common cause of USH1 (Ben-Yosef T, Ness SL, Madeo AC, Bar-Lev A, Wolfman JH, Ahmed ZM, Desnick RK, Willner JP, Avraham KB, Ostrer H, Oddoux C, Griffith AJ, Friedman TB N Engl J Med 348: 1664-1670, 2003). To estimate what percentage of Ashkenazi Jewish children born with profound hearing loss will develop RP due to R245X, we examined the prevalence of the R245X PCDH15 mutation and its carrier rate among Ashkenazi Jews in Israel. Among probands diagnosed with nonsyndromic hearing loss not due to mutations of connexin 26 (GJB2) and/or connexin 30 (GJB6), and below the age of 10, 2 of 20 (10%) were homozygous for the R245X mutation. Among older nonsyndromic deaf individuals, no homozygotes were detected, although one individual was heterozygous for R245X. The carrier rate of the R245X mutation among the normal hearing Ashkenazi population in Israel was estimated at 1%. Ashkenazi Jewish children with profound prelingual hearing loss should be evaluated for the R245X PCDH15 mutation and undergo ophthalmologic evaluation to determine whether they will develop RP. Rehabilitation can then begin before loss of vision. Early use of cochlear implants in such cases may rescue these individuals from a dual neurosensory deficit.

To expand the genotype/phenotype correlations in patients with autosomal dominant retinitispigmentosa (adRP) harboring PRPF8 variants. Two patients, a father and his daughter, harboring a novel p.PRPF8-Glu2331* variant, underwent ophthalmic examination at 3-year-interval, including fundus photography, fundus autofluorescence, optical coherence tomography, and ISCEV standard full field ERGs. All reported disease-causing PRPF8 variants were collected and localized in the PRPF8 and PRPF8/SNRNP200 protein structures. The p.PRPF8-Glu2331* variant results in a truncated PRPF8 protein lacking the last five C-terminal amino acids and caused in the two patients a severe clinical phenotype, with the macula being affected from the second decade on. All but two adRP-linked variants are located in the last exon 43 encoding the C-terminal tail of the C-terminal PRPF8 Jab1 domain. The p.PRPF8-Ser2118Phe and -Asn2280Lys variants encoded by exons 39 and 42, respectively, are located at the basis of the C-terminal tail. Frame-shift mutations and nonconservative amino acid changes in PRPF8 typically cause severe clinical phenotypes. The conservative missense variant p.PRPF8-Arg2310Lys that is not altering the global charge of the C-terminal tail, and variants located at the basis of the C-terminal tail show milder clinical phenotypes, in accordance with functional data on PRPF8/SNRNP200 interactions in yeast.

To discuss the clinicopathological findings in a patient with retinitispigmentosa (RP) accompanied by a vitamin E deficiency caused by an H101Q mutation in the alpha-tocopherol transfer protein (alpha-TTP) gene. The clinical course of this patient was followed by conventional ophthalmological examinations over a 3-year period. After the patient died from pancreatic cancer, the eyes were obtained, and examined by light and electron microscopy. The patient complained of night blindness subsequent to adult-onset ataxia, although the ataxia was very mild. His visual acuity was 0.6 OU, and ophthalmoscopy revealed RP sine pigmento. Ring scotomas were detected, and the electroretinography, electro-oculography, and dark-adaptation were altered. Fluorescein angiography showed granular hyperfluorescence around the macula. No progression of the visual and neurological symptoms was observed during the 10 years he was taking oral vitamin E. Histopathological examination revealed the loss of the outer and inner segments of the photoreceptors in the area corresponding to the ring scotoma, as well as a disorganization and shortening of the outer segments in the peripheral retina. We conclude that the clinical and pathological findings in the eyes of this patient having RP with vitamin E deficiency caused by an H101Q mutation are similar to those of common autosomal recessive RP. However, special attention is required in making a diagnosis of RP with vitamin E deficiency because RP with vitamin E deficiency is medically treatable. The mild Friedreich-type ataxia accompanying the RP may be helpful in identifying this disease.

Genetic loci for X-linked retinitispigmentosa (XLRP) have been mapped between Xp11.22 and Xp22.13 (RP2, RP3, RP6, and RP15). The RP3 gene, which is responsible for the predominant form of XLRP in most Caucasian populations, has been localized to Xp21.1 by linkage analysis and the map positions of chromosomal deletions associated with the disease. Previous linkage studies have suggested that RP3 is flanked by the markers DXS1110 (distal) and OTC (proximal). Patient BB was though to have RP because of a lesion at the RP3 locus, in addition to chronic granulomatous disease, Duchenne muscular dystrophy (DMD), mild mental retardation, and the McLeod phenotype. This patient carried a deletion extending {approximately}3 Mb from DMD in Xp21.3 to Xp21.1, with the proximal breakpoint located {approximately}40 kb centromeric to DXS1110. The RP3 gene, therefore, is believed to reside between DXS1110 and the proximal breakpoint of the BB deletion. In order to refine the location of RP3 and to ascertain patients with RP3, we have been analyzing several XLRP families for linkage to Xp markers. Linkage analysis in an American family of 27 individuals demonstrates segregation of XLRP with markers in Xp21.1, consistent with the RP3 subtype. One affected male shows a recombination event proximal to DXS1110. Additional markers within the DXS1110-OTC interval show that the crossover is between two novel polymorphic markers, DXS8349 and M6, both of which are present in BB DNA and lie centromeric to the proximal breakpoint. This recombination places the XLRP mutation in this family outside the BB deletion and redefines the location of RP3. 22 refs., 3 figs., 2 tabs.

Retinitispigmentosa (RP), a major cause of blindness in developed countries, has multiple causative genes; its prevalence differs by ethnicity. Usher syndrome is the most common form of syndromic RP and is accompanied by hearing impairment. Although molecular diagnosis is challenging, recent technological advances such as targeted high-throughput resequencing are efficient screening tools. We performed comprehensive molecular testing in 329 Japanese RP and Usher syndrome patients by using a custom capture panel that covered the coding exons and exon/intron boundaries of all 193 known inherited eye disease genes combined with Illumina HiSequation 2500. Candidate variants were screened using systematic data analyses, and their potential pathogenicity was assessed according to the frequency of the variants in normal populations, in silico prediction tools, and compatibility with known phenotypes or inheritance patterns. Molecular diagnoses were made in 115/317 RP patients (36.3%) and 6/12 Usher syndrome patients (50%). We identified 104 distinct mutations, including 66 novel mutations. EYS, USH2A, and RHO were common causative genes. In particular, mutations in EYS accounted for 15.0% of the autosomal recessive/simplex RP patients or 10.7% of the entire RP cohort. Among the 189 previously reported mutations detected in the current study, 55 (29.1%) were found commonly in Japanese or other public databases and were excluded from molecular diagnoses. By screening a large cohort of patients, this study catalogued the genetic variations involved in RP and Usher syndrome in a Japanese population and highlighted the different distribution of causative genes among populations. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

A screen of the entire coding region of the USH2A gene in 129 unrelated patients with Usher syndrome type II (USH2) and in 146 unrelated patients with non-syndromic autosomal recessive retinitispigmentosa (ARRP) uncovered 54 different sequence variations, including 18 likely pathogenic mutations (13 frameshift, three nonsense, and two missense), 12 changes of uncertain pathogenicity (11 missense changes and one in-frame deletion), and 24 non-pathogenic rare variants or polymorphisms. Of the 18 likely pathogenic mutations, nine were novel. Among the USH2 patients, 50 (39%) had one or two likely pathogenic mutations. The most common mutant allele in USH2 patients was E767fs, which was found in 29 patients, including one homozygote. Among the ARRP patients, we found 17 (12%) with one or two likely pathogenic mutations. The most common mutant allele in ARRP patients was C759F and it was found in 10 patients. The C759F allele was also found in two USH2 patients; in neither of them was a change in the other allele found. The second most common mutant allele in both patient groups was L1447fs (found in 6/50 USH2 patients and 6/17 ARRP patients). Of the 50+17=67 patients with identified USH2A mutations, only one mutation in one allele was found in 41+12=53 (79%); the reason for the high proportion of patients with only one identified mutation is obscure. Our results indicate that USH2A mutations are found in about 7% of all cases of RP in North America, a frequency similar to the RPGR gene (8%) and the rhodopsin gene (10%).

Objectives To determine the efficacy for sustained use of topical therapy with dorzolamide hydrochloride 2% on visual acuity and cystic macular lesions in retinitispigmentosa (RP) and Usher (USH) syndrome patients. Design Retrospective case series. Setting University hospital. Patients Sixty-four eyes of 32 patients with RP or USH syndrome who received treatment with topical dorzolamide formulation for a duration ranging from 6–58 months were enrolled. Main Outcome Measures Changes in visual acuity (ETDRS) and central foveal zone thickness on optical coherence tomography during follow-up for the duration of treatment. Results Among the study cohort, a positive response occurred in 20 of 32 patients (63%) in at least one eye and in 13 patients (41%) in both eyes. Four patients (20%) showed an initial response and a subsequent rebound of macular cysts. In 8 patients (25%) there was no response to treatment and the macular cysts worsened when compared with the pretreatment level. Ten patients (31%) had improvement in visual acuity by ≥7 letters in at least one eye at the most recent follow-up visit. Sixteen patients (67%) showed a reduction of >11% in the central foveal zone thickness in at least one eye when compared with the pretreatment level. Conclusion Treatment of cystoid macular edema with topical dorzolamide in patients with either RP or USH syndrome and followed by an OCT-guided strategy showed a decrease in central foveal zone thickness in the majority of cases. Visual acuity improved in almost 1/3 of the cases, suggesting a potential corresponding visual benefit. PMID:20837798

PURPOSE To detect the disease-causing gene in a Chinese pedigree with autosomal-recessive retinitispigmentosa (ARRP). METHODS All subjects in this family underwent a complete ophthalmic examination. Targeted-capture next generation sequencing (NGS) was performed on the proband to detect variants. All variants were verified in the remaining family members by PCR amplification and Sanger sequencing. RESULTS All the affected subjects in this pedigree were diagnosed with retinitispigmentosa (RP). The compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations in the Crumbs homolog 1 (CRB1) gene were identified in all the affected patients but not in the unaffected individuals in this family. These mutations were inherited from their parents, respectively. CONCLUSION The novel compound heterozygous mutations in CRB1 were identified in a Chinese pedigree with ARRP using targeted-capture next generation sequencing. After evaluating the significant heredity and impaired protein function, the compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations are the causal genes of early onset ARRP in this pedigree. To the best of our knowledge, there is no previous report regarding the compound mutations. PMID:27806333

Retinitispigmentosa (RP) is a genetically heterogeneous disease characterized by degeneration of the retina. Mutations in the RP2 gene are linked to the second most frequent form of X-linked retinitispigmentosa. RP2 is a plasma membrane-associated protein of unknown function. The N-terminal domain of RP2 shares amino acid sequence similarity to the tubulin-specific chaperone protein co-factor C. The C-terminus consists of a domain with similarity to nucleoside diphosphate kinases (NDKs). Human NDK1, in addition to its role in providing nucleoside triphosphates, has recently been described as a 3' to 5' exonuclease. Here, we show that RP2 is a DNA-binding protein that exhibits exonuclease activity, with a preference for single-stranded or nicked DNA substrates that occur as intermediates of base excision repair pathways. Furthermore, we show that RP2 undergoes re-localization into the nucleus upon treatment of cells with DNA damaging agents inducing oxidative stress, most notably solar simulated light and UVA radiation. The data suggest that RP2 may have previously unrecognized roles as a DNA damage response factor and 3' to 5' exonuclease

To evaluate the phenotype of 15 children with congenital hyperinsulinism (CHI) and profound hearing loss, known as Homozygous 11p15-p14 Deletion syndrome (MIM #606528). Prospective clinical follow-up and genetic analysis by direct sequencing, multiplex ligation-dependent probe amplification, and microsatellite markers. Genetic testing identified the previous described homozygous deletion in 11p15, USH1C:c.(90+592)_ABCC8:c.(2694-528)del. Fourteen patients had severe CHI demanding near-total pancreatectomy. In one patient with mild, transient neonatal hypoglycemia and nonautoimmune diabetes at age 11 years, no additional mutations were found in HNF1A, HNF4A, GCK, INS, and INSR. Retinitispigmentosa was found in two patients aged 9 and 13 years. No patients had enteropathy or renal tubular defects. Neuromotor development ranged from normal to severe delay with epilepsy. The phenotype of Homozygous 11p15-p14 Deletion syndrome, or Usher-CHI syndrome, includes any severity of neonatal-onset CHI and severe, sensorineural hearing loss. Retinitispigmentosa and nonautoimmune diabetes may occur in adolescence.

Retinitispigmentosa (RP) is the most common form of inherited blindness, caused by progressive degeneration of photoreceptor cells in the retina, and affects approximately 1 in 3,000 people. Over the past decade, significant progress has been made in gene therapy for RP and related diseases, making genetic characterization increasingly important. Recently, high-throughput technologies have provided an option for reasonably fast, cost-effective genetic characterization of autosomal recessive RP (arRP). The current study used a single nucleotide polymorphism (SNP) genotyping method to exclude up to 28 possible disease-causing genes in 31 non-consanguineous Australian families affected by arRP. DNA samples were collected from 59 individuals affected with arRP and 74 unaffected family members from 31 Australian families. Five to six SNPs were genotyped for 28 genes known to cause arRP or the related disease Leber congenital amaurosis (LCA). Cosegregation analyses were used to exclude possible causative genes from each of the 31 families. Bidirectional sequencing was used to identify disease-causing mutations in prioritized genes that were not excluded with cosegregation analyses. Two families were excluded from analysis due to identification of false paternity. An average of 28.9% of genes were excluded per family when only one affected individual was available, in contrast to an average of 71.4% or 89.8% of genes when either two, or three or more affected individuals were analyzed, respectively. A statistically significant relationship between the proportion of genes excluded and the number of affected individuals analyzed was identified using a multivariate regression model (pA) and USH2A in two families (c.2276 G>T). This study has shown that SNP genotyping cosegregation analysis can be successfully used to refine and expedite the genetic characterization of arRP in a non-consanguineous population; however, this method is effective only when DNA samples are

Full Text Available We have established an induced pluripotent stem (iPS cell line using urine-derived cells from a 27-year-old male patient with retinitispigmentosa associated with point mutations in the USH2A gene. Feeder-free culture conditions and the integration-free CytoTune™-iPS 2.0 Sendai Reprogramming Kit were used.

Purpose Autosomal dominant retinitispigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition. Methods Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations. Results Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5–30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%). Conclusions Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular

Full Text Available To investigate the association between retinitispigmentosa (RP and acute angle closure during a 15-year follow-up period.Using the Taiwan Longitudinal Health Insurance Database 2000, we identified 382 RP patients based on the diagnostic code of RP (International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM 362.74 made during 1996-2010, excluding subjects under age of 20 years at diagnosis or subjects undergoing lens extraction before the index date. The control group included 3820 randomly selected non-RP subjects matched with the RP patients in age, gender and the index date of diagnosis. The incidence of acute angle closure during the study period was observed based on an ICD-9-CM code of 365.22. Cochran-Mantel-Haenszel test was used to determine the odds ratio (OR of having acute angle closure in RP patients.The mean age at the diagnosis of RP was 51.1 years (standard deviation [SD] 16.7. Acute angle closure occurred in 5 RP patients (1.3% and in 15 controls (0.4%. The mean age with the acute angle closure was 53.3 years (SD 8.0 in RP patients and 64.6 years (SD 8.4 in controls (P = 0.015. After adjusting for age, gender and comorbid disorders, RP patients had 3.64-fold (95% confidence interval [CI], 1.29-10.25, P<0.001 greater odds of having acute angle closure. After stratification for gender and age, the risk of acute angle closure in RP was higher in patients under age of 60 years (adjusted OR 11.84; 95% CI, 2.84-49.48 and male patients (adjusted OR 19.36; 95% CI, 3.43-109.40 (both P = 0.001.RP patients had increased risk of acute angle closure than controls. Contrary to the fact that angle closure disease is more prevalent in elderly females in general population, acute angle closure attack occurred earlier in life and the risk was higher in males among RP patients.

Full Text Available Retinitispigmentosa (RP is a highly heterogeneous genetic disease including autosomal recessive (ar, autosomal dominant (ad, and X-linked inheritance. Recently, arRP has been associated with mutations in EYS (Eyes shut homolog, which is a major causative gene for this disease. This study was conducted to determine the spectrum and frequency of EYS mutations in 100 Japanese arRP patients. To determine the prevalence of EYS mutations, all EYS exons were screened for mutations by polymerase chain reaction amplification, and sequence analysis was performed. We detected 67 sequence alterations in EYS, of which 21 were novel. Of these, 7 were very likely pathogenic mutations, 6 were possible pathogenic mutations, and 54 were predicted non-pathogenic sequence alterations. The minimum observed prevalence of distinct EYS mutations in our study was 18% (18/100, comprising 9 patients with 2 very likely pathogenic mutations and the remaining 9 with only one such mutation. Among these mutations, 2 novel truncating mutations, c.4957_4958insA (p.S1653KfsX2 and c.8868C>A (p.Y2956X, were identified in 16 patients and accounted for 57.1% (20/35 alleles of the mutated alleles. Although these 2 truncating mutations were not detected in Japanese patients with adRP or Leber's congenital amaurosis, we detected them in Korean arRP patients. Similar to Japanese arRP results, the c.4957_4958insA mutation was more frequently detected than the c.8868C>A mutation. The 18% estimated prevalence of very likely pathogenic mutations in our study suggests a major involvement of EYS in the pathogenesis of arRP in the Japanese population. Mutation spectrum of EYS in 100 Japanese patients, including 13 distinct very likely and possible pathogenic mutations, was largely different from the previously reported spectrum in patients from non-Asian populations. Screening for c.4957_4958insA and c.8868C>A mutations in the EYS gene may therefore be very effective for the genetic testing

To describe the phenotype of members of the first Czech retinitispigmentosa family with an identified molecular genetic cause (c.2426_2427delAG in RPGR), followed for more than 13 years. Medical records were reviewed and a detailed ophthalmic examination including spectral-domain optical coherence tomography and full-field and multifocal electroretinography (ERG) was performed in two affected males, three female carriers and one unaffected female. A 22-year-old male who denied suffering from nyctalopia had a best corrected visual acuity (BCVA) of 0.63 in both eyes. Moderate myopia and myopic astigmatism were present bilaterally. Color vision and contrast sensitivity were normal. There was an eccentric constriction of the visual fields that spared the central 20 degrees in both eyes. Fundus examination revealed bilateral pigmentary changes in the mid-periphery. Full-field ERG documented a 10% rod and 20% cone response. The phenotype of his cousin, also aged 22 years, was more severe. He complained of nyctalopia since 12 years of age. His BCVA was 0.3 in the right eye and 0.5 in the left eye. Myopia and astigmatism were present bilaterally. Contrast sensitivity and color vision were severely impaired. Full field ERG was extinct, but some activity on multifocal ERG was still detectable. The constriction of the visual fields reached 5 degrees in both eyes. Fundus examination showed the typical retinitispigmentosa appearance. All carriers denied that they suffered from nyctalopia, but two of them had decreased BCVA in at least one eye. None exhibited typical bone spicules or a tapetal-like reflex. Significant refractive errors were present in all eyes of the carriers. The finding of moderate or high myopia and astigmatism in males with retinitispigmentosa as well as refractive errors in female relatives indicates possible X-linked inheritance, which may be especially important in pedigrees where the transmission pattern can not be clearly established. Our study

Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world's first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA) and has been given the CE-Mark for sale within the European Economic Area (EEA). The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitispigmentosa in an attempt to improve the anatomical and functional outcomes.

Full Text Available Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world’s first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA and has been given the CE-Mark for sale within the European Economic Area (EEA. The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitispigmentosa in an attempt to improve the anatomical and functional outcomes.

Full Text Available Abstract Background Single-gene disorders related to ischemic stroke seem to be an important cause of stroke in young patients without known risk factors. To identify new genes responsible of such diseases, we studied a consanguineous Moroccan family with three affected individuals displaying hereditary leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitispigmentosa that appears to segregate in autosomal recessive pattern. Methods All family members underwent neurological and radiological examinations. A genome wide search was conducted in this family using the ABI PRISM linkage mapping set version 2.5 from Applied Biosystems. Six candidate genes within the region linked to the disease were screened for mutations by direct sequencing. Results Evidence of linkage was obtained on chromosome 17q24.2-25.3. Analysis of recombination events and LOD score calculation suggests linkage of the responsible gene in a genetic interval of 11 Mb located between D17S789 and D17S1806 with a maximal multipoint LOD score of 2.90. Sequencing of seven candidate genes in this locus, ATP5H, FDXR, SLC25A19, MCT8, CYGB, KCNJ16 and GRIN2C, identified three missense mutations in the FDXR gene which were also found in a homozygous state in three healthy controls, suggesting that these variants are not disease-causing mutations in the family. Conclusion A novel locus for leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitispigmentosa has been mapped to chromosome 17q24.2-25.3 in a consanguineous Moroccan family.

Retinitispigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 45 genes. Recently, the FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. We performed a clinical and molecular genetic study of a consanguineous Palestinian family with two three siblings affected with retinitispigmentosa. DNA samples were collected from the index patient, his father, his affected sister, and two non-affected brothers. DNA sample from the index was subjected to high resolution genome-wide SNP array. Assuming identity-by-descent in this consanguineous family we applied homozygosity mapping to identify disease causing genes. The index patient reported night blindness since the age of 20 years, followed by moderate disease progression with decrease of peripheral vision, the development of photophobia and later on reduced central vision. At the age of 40 his visual acuity was counting fingers (CF) for both eyes, color discrimination was not possible and his visual fields were severely constricted. Funduscopic examination revealed a typical appearance of advanced RP with optic disc pallor, narrowed retinal vessels, bone-spicule like pigmentary changes in the mid-periphery and atrophic changes in the macula. His younger affected brother (37 years) was reported with overall milder symptoms, while the youngest sister (21 years) reported problems only with night vision. Applying high-density SNP arrays we identified several homozygous genomic regions one of which included the recently identified FAM161A gene mutated in RP28-linked autosomal recessive RP. Sequencing analysis revealed the presence of a novel homozygous nonsense mutation, c.1003C>T/p.R335X in the index patient and the affected sister. We identified an RP28-linked RP family in the Palestinian population caused by a novel nonsense mutation in FAM161A. RP in this family shows a typical disease onset with moderate to rapid progression

Full Text Available Background. Retinitispigmentosa (RP is an inherited retinal degenerative disease, which is clinically and genetically heterogeneous, and the inheritance pattern is complex. In this study, we have intended to study the possible association of certain genes with X-linked RP (XLRP in a Chinese family. Methods. A Chinese family with RP was recruited, and a total of seven individuals were enrolled in this genetic study. Genomic DNA was isolated from peripheral leukocytes, and used for the next generation sequencing (NGS. Results. The affected individual presented the clinical signs of XLRP. A heterozygous missense mutation (c.1555C>T, p.R519W was identified by NGS in exon 13 of the CACNA1F gene on X chromosome, and was confirmed by Sanger sequencing. It showed perfect cosegregation with the disease in the family. The mutation at this position in the CACNA1F gene of RP was found novel by database searching. Conclusion. By using NGS, we have found a novel heterozygous missense mutation (c.1555C>T, p.R519W in CACNA1F gene, which is probably associated with XLRP. The findings might provide new insights into the cause and diagnosis of RP, and have implications for genetic counseling and clinical management in this family.

Retinitispigmentosa (RP) is a group of inherited retinal disorders characterized by a complex association between tremendous genotypic multiplicity and great phenotypic heterogeneity. The severity of the clinical manifestation depends on penetrance and expressivity of the disease-gene. Also, various interactions between gene expression and environmental factors have been hypothesized. More than 250 genes with ~4500 causative mutations have been reported to be involved in different RP-related mechanisms. Nowadays, not more than the 50% of RPs are attributable to identified genes, whereas the rest of molecular defects are still undetectable, especially in populations where few genetic screenings have been performed. Therefore, new genetic strategies can be a remarkably useful tool to aid clinical diagnosis, potentially modifying treatment options, and family counseling. Genome-wide analytical techniques (array comparative genomic hybridization and single-nucleotide polymorphism genotyping) and DNA sequencing strategies (arrayed primer extension, Sanger sequencing, and ultra high-throughput sequencing) are successfully used to early make molecular diagnosis detecting single or multiple mutations in the huge heterogeneity of RPs. To date, further research needs to be carried out to better investigate the genotype/phenotype correlation, putting together genetic and clinical findings to provide detailed information concerning the risk of RP development and novel effective treatments. PMID:27564722

Mutations in the ABCA4 gene have been associated with autosomal recessive Stargardt disease (STGD1), cone-rod dystrophy (CRD), and retinitispigmentosa (RP). We employed a recently developed genotyping microarray, the ABCR400-chip, to search for known ABCA4 mutations in patients with isolated or autosomal recessive CRD (54 cases) or RP (90 cases). We performed detailed ophthalmologic examinations and identified at least one ABCA4 mutation in 18 patients (33%) with CRD and in five patients (5.6%) with RP. Single-strand conformation polymorphism (SSCP) analysis and subsequent DNA sequencing revealed four novel missense mutations (R24C, E161K, P597S, G618E) and a novel 1-bp deletion (5888delG). Ophthalmoscopic abnormalities in CRD patients ranged from minor granular pigmentary changes in the posterior pole to widespread atrophy. In 12 patients with recordable electroretinogram (ERG) tracings, a cone-rod pattern was detected. Three patients demonstrated progression from a retinal dystrophy resembling STGD1 to a more widespread degeneration, and were subsequently diagnosed as CRD. In addition to a variable degree of atrophy, all RP patients displayed ophthalmologic characteristics of classic RP. When detectable, ERG recordings in these patients demonstrated rod-cone patterns of photoreceptor degeneration. In conclusion, in this study, we show that the ABCA4 mutation chip is an efficient first screening tool for arCRD.

Retinitispigmentosa (RP), the most genetically heterogeneous disorder in humans, actually represents a group of pigmentary retinopathies characterized by night blindness followed by visual-field loss. RP can appear as either syndromic or nonsyndromic. One of the most common forms of syndromic RP is Usher syndrome, characterized by the combination of RP, hearing loss, and vestibular dysfunction. The underlying cause of the appearance of syndromic and nonsyndromic RP in three siblings from a consanguineous Israeli Muslim Arab family was studied with whole-genome homozygosity mapping followed by whole exome sequencing. THE FAMILY WAS FOUND TO SEGREGATE NOVEL MUTATIONS OF TWO DIFFERENT GENES: myosin VIIA (MYO7A), which causes type 1 Usher syndrome, and phosphodiesterase 6B, cyclic guanosine monophosphate-specific, rod, beta (PDE6B), which causes nonsyndromic RP. One affected child was homozygous for both mutations. Since the retinal phenotype seen in this patient results from overlapping pathologies, one might expect to find severe retinal degeneration. Indeed, he was diagnosed with RP based on an abnormal electroretinogram (ERG) at a young age (9 months). However, this early diagnosis may be biased, as two of his older siblings had already been diagnosed, leading to increased awareness. At the age of 32 months, he had relatively good vision with normal visual fields. Further testing of visual function and structure at different ages in the three siblings is needed to determine whether the two RP-causing genes mutated in this youngest sibling confer increased disease severity. This report further supports the genetic heterogeneity of RP, and demonstrates how consanguinity could increase intrafamilial clustering of multiple hereditary diseases. Moreover, this report provides a unique opportunity to study the clinical implications of the coexistence of pathogenic mutations in two RP-causative genes in a human patient.

Purpose Retinitispigmentosa (RP), the most genetically heterogeneous disorder in humans, actually represents a group of pigmentary retinopathies characterized by night blindness followed by visual-field loss. RP can appear as either syndromic or nonsyndromic. One of the most common forms of syndromic RP is Usher syndrome, characterized by the combination of RP, hearing loss, and vestibular dysfunction. Methods The underlying cause of the appearance of syndromic and nonsyndromic RP in three siblings from a consanguineous Israeli Muslim Arab family was studied with whole-genome homozygosity mapping followed by whole exome sequencing. Results The family was found to segregate novel mutations of two different genes: myosin VIIA (MYO7A), which causes type 1 Usher syndrome, and phosphodiesterase 6B, cyclic guanosine monophosphate-specific, rod, beta (PDE6B), which causes nonsyndromic RP. One affected child was homozygous for both mutations. Since the retinal phenotype seen in this patient results from overlapping pathologies, one might expect to find severe retinal degeneration. Indeed, he was diagnosed with RP based on an abnormal electroretinogram (ERG) at a young age (9 months). However, this early diagnosis may be biased, as two of his older siblings had already been diagnosed, leading to increased awareness. At the age of 32 months, he had relatively good vision with normal visual fields. Further testing of visual function and structure at different ages in the three siblings is needed to determine whether the two RP-causing genes mutated in this youngest sibling confer increased disease severity. Conclusions This report further supports the genetic heterogeneity of RP, and demonstrates how consanguinity could increase intrafamilial clustering of multiple hereditary diseases. Moreover, this report provides a unique opportunity to study the clinical implications of the coexistence of pathogenic mutations in two RP-causative genes in a human patient. PMID:23882135

A patient initially presented with constricted visual field, attenuated retinal vasculature, pigmentary clumping and reduced ERG in OS only, suggestive of unilateral retinitispigmentosa (RP). This patient was subsequently seen on eight occasions (over three decades), and, with time, the initially normal eye (OD) gradually showed signs of RP-like degeneration. The purpose of this study was to evaluate which clinical modality (visual field, funduscopy or electroretinography) could have first predicted this fate. At each time points, data obtained from our patient were compared to normative data using Z tests. At initial visit, all tests were significantly (p retinal vessel diameter in OD reduced gradually to reach statistical significance at the 5th visit and 6th visit (21 and 22 years after the first examination, respectively). In OD, the amplitude of the scotopic and photopic ERGs reduced gradually and was significantly smaller than normal at the 2nd visit (after 11 years) and 3rd visit (after 18 years), respectively. When the photopic ERG was analyzed using the discrete wavelet transform (DWT), we were able to detect a significant change at the 2nd visit (after 11 years) instead of the 3rd visit (18 years). Our study allowed us to witness the earliest manifestation of an RP disease process. The ERG was the first test to detect significant RP changes. A significantly earlier detection of ERG anomalies was obtained when the DWT was used, demonstrating its advantage for early detection of ERG changes.

Usher syndrome is an autosomal recessive condition characterized by sensorineural hearing loss, variable vestibular dysfunction, and visual impairment due to retinitispigmentosa (RP). The seven proteins that have been identified for Usher syndrome type 1 (USH1) and type 2 (USH2) may interact in a large protein complex. In order to identify novel USH genes, we followed a candidate strategy, assuming that mutations in proteins interacting with this "USH network" may cause Usher syndrome as well. The DFNB31 gene encodes whirlin, a PDZ scaffold protein with expression in both hair cell stereocilia and retinal photoreceptor cells. Whirlin represents an excellent candidate for USH2 because it binds to Usherin (USH2A) and VLGR1b (USH2C). Genotyping of microsatellite markers specific for the DFNB31 gene locus on chromosome 9q32 was performed in a German USH2 family that had been excluded for all known USH loci. Patients showed common haplotypes. Sequence analysis of DFNB31 revealed compound heterozygosity for a nonsense mutation, p.Q103X, in exon 1, and a mutation in the splice donor site of exon 2, c.837+1G>A. DFNB31 mutations appear to be a rare cause of Usher syndrome, since no mutations were identified in an additional 96 USH2 patients. While mutations in the C-terminal half of whirlin have previously been reported in non-syndromic deafness (DFNB31), both alterations identified in our USH2 family affect the long protein isoform. We propose that mutations causing Usher syndrome are probably restricted to exons 1-6 that are specific for the long isoform and probably crucial for retinal function. We describe a novel genetic subtype for Usher syndrome, which we named USH2D and which is caused by mutations in whirlin. Moreover, this is the first case of USH2 that is allelic to non-syndromic deafness.

Full Text Available The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced, autoimmune (experimental autoimmune encephalomyelitis, mechanical stress (optic nerve crush-induced, light-induced and ischemia (transient retinal ischemia-induced. The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insight into the underlying mechanisms of the disease, and will facilitate the development of novel effective therapeutic drugs to treat retinal cell damage.

To describe the clinical and genetic findings in one Chinese family with autosomal recessive retinitispigmentosa (arRP) and in three unrelated Chinese families with Usher syndrome type II (USH2). One family (FR1) with arRP and three unrelated families (F6, F7, and F8) with Usher syndrome (USH), including eight affected members and seven unaffected family individuals were examined clinically. The study included 100 normal Chinese individuals as normal controls. After obtaining informed consent, peripheral blood samples from all participants were collected and genomic DNA was extracted. Genotyping and haplotyping analyses were performed on the known genetic loci for arRP with a panel of polymorphic markers in family FR1. In all four families, the coding region (exons 2-72), including the intron-exon boundary of the USH2A (Usher syndrome type -2A protein) gene, was screened by PCR and direct DNA sequencing. Whenever substitutions were identified in a patient, a restriction fragment length polymorphism (RFLP) analysis, single strand conformation polymorphism (SSCP) analysis, or high resolution melt curve analysis (HRM) was performed on all available family members and on the 100 normal controls. The affected individuals presented with typical fundus features of retinitispigmentosa (RP), including narrowing of the vessels, bone-spicule pigmentation, and waxy optic discs. The electroretinogram (ERG) wave amplitudes of the available probands were undetectable. Audiometric tests in the affected individuals in family FR1 were normal, while indicating moderate to severe sensorineural hearing impairment in the affected individuals in families F6, F7, and F8. Vestibular function was normal in all patients from all four families. The disease-causing gene in family FR1 was mapped to the USH2A locus on chromosome 1q41. Seven novel mutations (two missenses, one 7-bp deletion, two small deletions, and two nonsenses) were detected in the four families after sequencing analysis of

Full Text Available Mutations in RPGR account for over 70% of X-linked retinitispigmentosa (XlRP, characterized by retinal degeneration and eventual blindness. The clinical consequences of RPGR mutations are highly varied, even among individuals with the same mutation: males demonstrate a wide range of clinical severity, and female carriers may or may not be affected. This study describes the phenotypic diversity in a cohort of 98 affected males from 56 families with RPGR mutations, and demonstrates the contribution of genetic factors (i.e., allelic heterogeneity and genetic modifiers to this diversity. Patients were categorized as grade 1 (mild, 2 (moderate or 3 (severe according to specific clinical criteria. Patient DNAs were genotyped for coding SNPs in 4 candidate modifier genes with products known to interact with RPGR protein: RPGRIP1, RPGRIP1L, CEP290, and IQCB1. Family-based association testing was performed using PLINK. A wide range of clinical severity was observed both between and within families. Patients with mutations in exons 1-14 were more severely affected than those with ORF15 mutations, and patients with predicted null alleles were more severely affected than those predicted to make RPGR protein. Two SNPs showed association with severe disease: the minor allele (N of I393N in IQCB1 (p = 0.044 and the common allele (R of R744Q in RPGRIP1L (p = 0.049. These data demonstrate that allelic heterogeneity contributes to phenotypic diversity in XlRP and suggest that this may depend on the presence or absence of RPGR protein. In addition, common variants in 2 proteins known to interact with RPGR are associated with severe disease in this cohort.

Full Text Available Abstract Background Retinitispigmentosa (RP, a clinically and genetically heterogeneous group of retinal degeneration disorders affecting the photoreceptor cells, is one of the leading causes of genetic blindness. Mutations in the photoreceptor-specific gene RP1 account for 3–10% of cases of autosomal dominant RP (adRP. Most of these mutations are clustered in a 500 bp region of exon 4 of RP1. Methods Denaturing gradient gel electrophoresis (DGGE analysis and direct genomic sequencing were used to evaluate the 5' coding region of exon 4 of the RP1 gene for mutations in 150 unrelated index adRP patients. Ophthalmic and electrophysiological examination of RP patients and relatives according to pre-existing protocols were carried out. Results Three novel disease-causing mutations in RP1 were detected: Q686X, K705fsX712 and K722fsX737, predicting truncated proteins. One novel missense mutation, Thr752Met, was detected in one family but the mutation does not co-segregate in the family, thereby excluding this amino acid variation in the protein as a cause of the disease. We found the Arg677Ter mutation, previously reported in other populations, in two independent families, confirming that this mutation is also present in a Spanish population. Conclusion Most of the mutations reported in the RP1 gene associated with adRP are expected to encode mutant truncated proteins that are approximately one third or half of the size of wild type protein. Patients with mutations in RP1 showed mild RP with variability in phenotype severity. We also observed several cases of non-penetrant mutations.

P23H is the most common mutation in the RHODOPSIN (RHO) gene leading to a dominant form of retinitispigmentosa (RP), a rod photoreceptor degeneration that invariably causes vision loss. Specific disruption of the disease P23H RHO mutant while preserving the wild-type (WT) functional allele would be an invaluable therapy for this disease. However, various technologies tested in the past failed to achieve effective changes and consequently therapeutic benefits. We validated a CRISPR/Cas9 strategy to specifically inactivate the P23H RHO mutant, while preserving the WT allele in vitro. We, then, translated this approach in vivo by delivering the CRISPR/Cas9 components in murine Rho+/P23H mutant retinae. Targeted retinae presented a high rate of cleavage in the P23H but not WT Rho allele. This gene manipulation was sufficient to slow photoreceptor degeneration and improve retinal functions. To improve the translational potential of our approach, we tested intravitreal delivery of this system by means of adeno-associated viruses (AAVs). To this purpose, the employment of the AAV9-PHP.B resulted the most effective in disrupting the P23H Rho mutant. Finally, this approach was translated successfully in human cells engineered with the homozygous P23H RHO gene mutation. Overall, this is a significant proof-of-concept that gene allele specific targeting by CRISPR/Cas9 technology is specific and efficient and represents an unprecedented tool for treating RP and more broadly dominant genetic human disorders affecting the eye, as well as other tissues.

Body mass index (BMI) is the most commonly used quantitative measure of adiposity. It is a kind of complex genetic diseases which are caused by multiple susceptibility genes. The first intron of fat mass and obesity-associated (FTO) has been widely discovered to be associated with BMI. Retinitispigmentosa GTPase regulator-interacting protein-1 like (RPGRIP1L) is located in the upstream region of FTO and has been proved to be linked with obesity through functional tests. We carried out a genetic association analysis to figure out the role of the FTO gene and the RPGRIP1L gene in BMI. A quantitative traits study with 6,102 Chinese female samples, adjusted for age, was performed during our project. Among the twelve SNPs, rs1421085, rs1558902, rs17817449, rs8050136, rs9939609, rs7202296, rs56137030, rs9930506 and rs12149832 in the FTO gene were significantly associated with BMI after Bonferroni correction. Meanwhile, rs9934800 in the RPGRIP1L gene showed significance with BMI before Bonferroni correction, but this association was eliminated after Bonferroni correction. Our results suggested that genetic variants in the FTO gene were strongly associated with BMI in Chinese women, which may serve as targets of pharmaceutical research and development concerning BMI. Meanwhile, we didn't found the significant association between RPGRIP1L and BMI in Chinese women.

The purpose of this study was to determine the long-term efficacy and safety of valproic acid (VPA) treatment in patients with pigmentary retinal dystrophies. A retrospective chart review was conducted on 31 patients with a diagnosis of pigmentary retinal dystrophy prescribed VPA at a single centre. Visual field (VF), visual acuity (VA), length of treatment, liver enzymes and side effects were analysed. VF areas were defined using Goldmann VF (GVF) tracings recorded before, during and after VPA treatment using the V4e isopter for each eye. Using custom software, planimetric areas of VF were calculated. Five of the patients (10 eyes) had two Goldmann VF tracings, allowing comparison between baseline and follow-up VF. After 9.8 months of VPA, VF decreased by 0.145 cm(2) (26.478%) (p=0.432). For 22 of the patients (41 eyes), VA data was available, and logarithm of the minimum angle of resolution (logMAR) score changed by 0.056 log units (representing a decline in VA) after 14.9 months on VPA (p=0.002). Twelve patients (38.7%) reported negative side effects related to VPA use. VPA plays a complex role in patients with pigmentary retinal dystrophies and may be associated with VA and field decline as well as adverse side effects. Physicians should use caution with using VPA for pigmentary retinal dystrophies.

Retinal detachment is a rare complication in patients with retinitispigmentosa. A case is reported of tractional retinal detachment in a patient with retinitispigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitispigmentosa.

The degeneration of photoreceptors in the retina is one of the major causes of adult blindness in humans. Unfortunately, no effective clinical treatments exist for the majority of retinal degenerative disorders. Here we report on the fabrication and functional validation of a fully organic prosthesis for long-term in vivo subretinal implantation in the eye of Royal College of Surgeons rats, a widely recognized model of retinitispigmentosa. Electrophysiological and behavioural analyses reveal a prosthesis-dependent recovery of light sensitivity and visual acuity that persists up to 6-10 months after surgery. The rescue of the visual function is accompanied by an increase in the basal metabolic activity of the primary visual cortex, as demonstrated by positron emission tomography imaging. Our results highlight the possibility of developing a new generation of fully organic, highly biocompatible and functionally autonomous photovoltaic prostheses for subretinal implants to treat degenerative blindness.

Genetic and physical mapping of the RP17 locus on 17q identified a 3.6-megabase candidate region that includes the gene encoding carbonic anhydrase IV (CA4), a glycosylphosphatidylinositol-anchored protein that is highly expressed in the choriocapillaris of the human eye. By sequencing candidate genes in this region, we identified a mutation that causes replacement of an arginine with a tryptophan (R14W) in the signal sequence of the CA4 gene at position -5 relative to the signal sequence cleavage site. This mutation was found to cosegregate with the disease phenotype in two large families and was not found in 36 unaffected family members or 100 controls. Expression of the mutant cDNA in COS-7 cells produced several findings, suggesting a mechanism by which the mutation can explain the autosomal dominant disease. In transfected COS-7 cells, the R14W mutation (i) reduced the steady-state level of carbonic anhydrase IV activity expressed by 28% due to a combination of decreased synthesis and accelerated turnover; (ii) led to up-regulation of immunoglobulin-binding protein, double-stranded RNA-regulated protein kinase-like ER kinase, and CCAAT/enhancer-binding protein homologous protein, markers of the unfolded protein response and endoplasmic reticulum stress; and (iii) induced apoptosis, as evidenced by annexin V binding and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining, in most cells expressing the mutant, but not the WT, protein. We suggest that a high level of expression of the mutant allele in the endothelial cells of the choriocapillaris leads to apoptosis, leading in turn to ischemia in the overlying retina and producing autosomal dominant retinitispigmentosa. PMID:15090652

To evaluate changes in the visual processing of patients with progressive retinitispigmentosa (RP) who acquired improved reading capability by eye-movement training (EMT), we performed functional magnetic resonance imaging (fMRI) before and after EMT. Six patients with bilateral concentric contraction caused by pigmentary degeneration of the retina and 6 normal volunteers were recruited. Patients were given EMT for 5 min every day for 8-10 months. fMRI data were acquired on a 3.0-Tesla scanner while subjects were performing reading tasks. In separate experiments (before fMRI scanning), visual performances for readings were measured by the number of letters read correctly in 5 min. Before EMT, activation areas of the primary visual cortex of patients were 48.8% of those of the controls. The number of letters read correctly in 5 min was 36.6% of those by the normal volunteers. After EMT, the activation areas of patients were not changed or slightly decreased; however, reading performance increased in 5 of 6 patients, which was 46.6% of that of the normal volunteers (p

Full Text Available To evaluate changes in the visual processing of patients with progressive retinitispigmentosa (RP who acquired improved reading capability by eye-movement training (EMT, we performed functional magnetic resonance imaging (fMRI before and after EMT. Six patients with bilateral concentric contraction caused by pigmentary degeneration of the retina and 6 normal volunteers were recruited. Patients were given EMT for 5 min every day for 8–10 months. fMRI data were acquired on a 3.0-Tesla scanner while subjects were performing reading tasks. In separate experiments (before fMRI scanning, visual performances for readings were measured by the number of letters read correctly in 5 min. Before EMT, activation areas of the primary visual cortex of patients were 48.8% of those of the controls. The number of letters read correctly in 5 min was 36.6% of those by the normal volunteers. After EMT, the activation areas of patients were not changed or slightly decreased; however, reading performance increased in 5 of 6 patients, which was 46.6% of that of the normal volunteers (p

Usher syndrome type II (USH2) is an autosomal recessive disorder characterised by retinitispigmentosa (RP) and mild to moderate sensorineural hearing loss. Mutations in the USH2A gene are the most common cause of USH2 and are also a cause of some forms of RP without hearing loss (ie, non-syndromic RP). The USH2A gene was initially identified as a transcript comprised of 21 exons but subsequently a longer isoform containing 72 exons was identified. The 51 exons unique to the long isoform of USH2A were screened for mutations among a core set of 108 patients diagnosed with USH2 and 80 patients with non-syndromic RP who were all included in a previously reported screen of the short isoform of USH2A. For several exons, additional patients were screened. In total, 35 deleterious mutations were identified including 17 nonsense mutations, 9 frameshift mutations, 5 splice-site mutations, and 4 small in-frame deletions or insertions. Twenty-seven mutations were novel. In addition, 65 rare missense changes were identified. A method of classifying the deleterious effect of the missense changes was developed using the summed results of four different mutation assessment algorithms, SIFT, pMUT, PolyPhen, and AGVGD. This system classified 8 of the 65 changes as 'likely deleterious' and 9 as 'possibly deleterious'. At least one mutation was identified in 57-63% of USH2 cases and 19-23% of cases of non-syndromic recessive RP (calculated without and including probable/possible deleterious changes) thus supporting that USH2A is the most common known cause of RP in the USA.

To assess the significance and evolution of parafoveal rings of high-density fundus autofluorescence (AF) in 12 patients with retinitispigmentosa (RP). Twelve patients with autosomal recessive RP or Usher syndrome type 2 were ascertained who had a parafoveal ring of high-density AF and a visual acuity of 20/30 or better at baseline. Photopic and scotopic fine matrix mapping (FMM) were performed to test sensitivity across the macula. AF imaging and FMM were repeated after 4 to 8 years and optical coherence tomography (OCT) performed. The size of the AF ring reduced over time and disappeared in one subject. Photopic thresholds were normal over the fovea; thresholds were elevated by 0.6 log units over the ring and by 1.2 log units external to the ring at baseline and differed by less than 0.1 log unit at follow-up. Mild photopic losses close to the internal edge of the ring were detected at baseline or follow-up in all. Mean scotopic thresholds over parafoveal areas within the ring were markedly elevated in 8 of 10 at baseline and were severely elevated in 9 of 11 at follow-up. The eccentricity of the inner edge of the AF ring corresponded closely with the lateral extent of the inner segment ellipsoid band in the OCT image. Ring constriction was largely coincident with progressive centripetal photopic threshold elevation led by worsening of rod photoreceptor function. The rate of constriction differed across patients, and a ring may reach a critical minimum before disappearing, at which stage central visual loss occurs. The structural and functional changes associated with rings of increased autofluorescence confirm that they provide an objective index of macular involvement and may aid the management of RP patients and the monitoring of future treatment efficacy.

Retinitispigmentosa (RP) is an inherited retinal dystrophy characterized by extreme genetic and clinical heterogeneity. Thus, the diagnosis is not always easily performed due to phenotypic and genetic overlap. Current clinical practices have focused on the systematic evaluation of a set of known genes for each phenotype, but this approach may fail in patients with inaccurate diagnosis or infrequent genetic cause. In the present study, we investigated the genetic cause of autosomal recessive RP (arRP) in a Spanish family in which the causal mutation has not yet been identified with primer extension technology and resequencing. We designed a whole-exome sequencing (WES)-based approach using NimbleGen SeqCap EZ Exome V3 sample preparation kit and the SOLiD 5500×l next-generation sequencing platform. We sequenced the exomes of both unaffected parents and two affected siblings. Exome analysis resulted in the identification of 43,204 variants in the index patient. All variants passing filter criteria were validated with Sanger sequencing to confirm familial segregation and absence in the control population. In silico prediction tools were used to determine mutational impact on protein function and the structure of the identified variants. Novel Usher syndrome type 2A (USH2A) compound heterozygous mutations, c.4325T>C (p.F1442S) and c.15188T>G (p.L5063R), located in exons 20 and 70, respectively, were identified as probable causative mutations for RP in this family. Family segregation of the variants showed the presence of both mutations in all affected members and in two siblings who were apparently asymptomatic at the time of family ascertainment. Clinical reassessment confirmed the diagnosis of RP in these patients. Using WES, we identified two heterozygous novel mutations in USH2A as the most likely disease-causing variants in a Spanish family diagnosed with arRP in which the cause of the disease had not yet been identified with commonly used techniques. Our data

Full Text Available Retinitispigmentosa (RP is a group of inherited retinopathies characterized by photoreceptors death. Our group has shown the positive progesterone (P4 actions on cell death progression in an experimental model of RP. In an effort to enhance the beneficial effects of P4, the aim of this study was to combine P4 treatment with an antioxidant [lipoic acid (LA] in the rd1 mice. rd1 and control mice were treated with 100 mg/kg body weight of P4, LA, or a combination of both on postnatal day 7 (PN7, 9, and 11, and were sacrificed at PN11. The administration of LA and/or P4 diminishes cell death in rd1 retinas. The effect obtained after the combined administration of LA and P4 is higher than the one obtained with LA or P4 alone. The three treatments decreased GFAP staining, however, in the far peripheral retina, and the two treatments that offered better results were LA and LA plus P4. LA or LA plus P4 increased retinal glutathione (GSH concentration in the rd1 mice. Although LA and P4 are able to protect photoreceptors from death in rd1 mice retinas, a better effectiveness is achieved when administering LA and P4 at the same time.

The purpose of this study was to evaluate clinical course of retinitispigmentosa taking into consideration models of inheritance and possible treatment. Retinitispigmentosa belongs to heterogeneous group of hereditary disorders, which are connected with gradual loss of the photoreceptor function, firstly rod cells subsequently cones, which is accompanied by the retinal pigmentary epithelium disorder. Retinitispigmentosa connected with X chromosome is one of the most severe form of this disease that in polish population takes place with frequency at average 10-15% which is similar to ADRP--10-20%. Course of RP, despite many similarities may differ from each other and prognosis depends on model of inheritance. Unfortunately, in spite of many efforts, nowadays medicine do not have successful treatment for patients with RP.

phenomenon has been described in many disorders linked to x chromosome, including blindness to color, hemophylia A or B, Duchenne's muscular distrophy and various ocular disorders linked to x chromosome. A clinical genetical study of a family with diagnosis of typical retinitispigmentosa of recessive heredity linked to x chromosome, where the phenomenon of unfavorable lyonization is present, was conducted

Usher syndrome is a group of autosomal recessive diseases characterized by congenital deafness and retinitispigmentosa. In a mouse model for Usher syndrome, KMush/ush, discovered in our laboratory, we measured the phenotypes, characterized the architecture and morphology of the retina, and quantified the level of expression of pde6b and ush2a between postnatal (P) days 7, and 56. Electroretinograms and auditory brainstem response were used to measure visual and auditory phenotypes. Fundus photography and light microscopy were used to measure the architecture and morphology of the retina. Quantitative real-time PCR was used to measure the expression levels of mRNA. KMush/ush mice had low amplitudes and no obvious waveforms of Electroretinograms after P14 compared with controls. Thresholds of auditory brainstem response in our model were higher than those of controls after P14. By P21, the retinal vessels of KMush/ush mice were attenuated and their optic discs had a waxy pallor. The retinas of KMush/ush mice atrophied and the choroidal vessels were clearly visible. Notably, the architecture of each retinal layer was not different as compared with control mice at P7, while the outer nuclear layer (ONL) and other retinal layers of KMush/ush mice were attenuated significantly between P14 and P21. ONL cells were barely seen in KMush/ush mice at P56. As compared with control mice, the expression of pde6b and ush2a in KMush/ush mice declined significantly after P7. This study is a first step toward characterizing the progression of disease in our mouse model. Future studies using this model may provide insights about the etiology of the disease and the relationships between genotypes and phenotypes providing a valuable resource that could contribute to the foundation of knowledge necessary to develop therapies to prevent the retinal degeneration in patients with Usher Syndrome.

Full Text Available Usher syndrome is a group of autosomal recessive diseases characterized by congenital deafness and retinitispigmentosa. In a mouse model for Usher syndrome, KMush/ush, discovered in our laboratory, we measured the phenotypes, characterized the architecture and morphology of the retina, and quantified the level of expression of pde6b and ush2a between postnatal (P days 7, and 56. Electroretinograms and auditory brainstem response were used to measure visual and auditory phenotypes. Fundus photography and light microscopy were used to measure the architecture and morphology of the retina. Quantitative real-time PCR was used to measure the expression levels of mRNA. KMush/ush mice had low amplitudes and no obvious waveforms of Electroretinograms after P14 compared with controls. Thresholds of auditory brainstem response in our model were higher than those of controls after P14. By P21, the retinal vessels of KMush/ush mice were attenuated and their optic discs had a waxy pallor. The retinas of KMush/ush mice atrophied and the choroidal vessels were clearly visible. Notably, the architecture of each retinal layer was not different as compared with control mice at P7, while the outer nuclear layer (ONL and other retinal layers of KMush/ush mice were attenuated significantly between P14 and P21. ONL cells were barely seen in KMush/ush mice at P56. As compared with control mice, the expression of pde6b and ush2a in KMush/ush mice declined significantly after P7. This study is a first step toward characterizing the progression of disease in our mouse model. Future studies using this model may provide insights about the etiology of the disease and the relationships between genotypes and phenotypes providing a valuable resource that could contribute to the foundation of knowledge necessary to develop therapies to prevent the retinal degeneration in patients with Usher Syndrome.

Genetic heterogeneity is a phenomenon in which a genetic disease can be transmitted by several modes of inheritance. The understanding of genetic heterogeneity is important in giving genetic counselling.The presence of genetic heterogeneity can be explained by the existence of:1.different mutant alleles at a single locus, and2.mutant alleles at different loci affecting the same enzyme or protein, or affecting different enzymes or proteins.To have an overall understanding of genetic heterogene...

Full Text Available Saffron, an extract from Crocus sativus, has been largely used in traditional medicine for its antiapoptotic and anticarcinogenic properties. In this work, we investigate the effects of safranal, a component of saffron stigmas, in attenuating retinal degeneration in the P23H rat model of autosomal dominant retinitispigmentosa. We demonstrate that administration of safranal to homozygous P23H line-3 rats preserves both photoreceptor morphology and number. Electroretinographic recordings showed higher a- and b-wave amplitudes under both photopic and scotopic conditions in safranal-treated versus non-treated animals. Furthermore, the capillary network in safranal-treated animals was preserved, unlike that found in untreated animals. Our findings indicate that dietary supplementation with safranal slows photoreceptor cell degeneration and ameliorates the loss of retinal function and vascular network disruption in P23H rats. This work also suggests that safranal could be potentially useful to retard retinal degeneration in patients with retinitispigmentosa.

X-linked congenital stationary night blindness (CSNBX) is a non-progressive retinal disorder characterized by decreased visual acuity and loss of night vision. CSNBX is clinically heterogeneous with respect to the involvement of retinal rods and/or cones in the disease. In this study, we localize a

Vision incapacitation and blindness associated with retinal dystrophies affect millions of people worldwide. Retinal degeneration is characterized by photoreceptor cell death and concomitant remodeling of remaining retinal cells. Repetitive Magnetic Stimulation (RMS) is a non-invasive technique that creates alternating magnetic fields by brief electric currents transmitted through an insulated coil. These magnetic field generate action potentials in neurons, and modulate the expression of neurotransmitter receptors, growth factors and transcription factors which mediate plasticity. This technology has been proven effective and safe in various psychiatric disorders. Here we determined the effect of RMS on retinal function in Royal College of Surgeons (RCS) rats, a model for retinal dystrophy. Four week-old RCS and control Spargue Dawley (SD) rats received sham or RMS treatment over the right eye (12 sessions on 4 weeks). RMS treatment at intensity of at 40% of the maximal output of a Rapid2 stimulator significantly increased the electroretinogram (ERG) b-wave responses by up to 6- or 10-fold in the left and right eye respectively, 3-5 weeks following end of treatment. RMS treatment at intensity of 25% of the maximal output did not significant effect b-wave responses following end of treatment with no adverse effect on ERG response or retinal structure of SD rats. Our findings suggest that RMS treatment induces delayed improvement of retinal functions and may induce plasticity in the retinal tissue. Furthermore, this non-invasive treatment may possibly be used in the future as a primary or adjuvant treatment for retinal dystrophy.

Full Text Available BACKGROUND: Retinitispigmentosa (RP is characterized by progressive night blindness, visual field loss, altered vascular permeability and loss of central vision. Currently there is no effective treatment available except gene replacement therapy has shown promise in a few patients with specific gene defects. There is an urgent need to develop therapies that offer generic neuro-and vascular-protective effects with non-invasive intervention. Here we explored the potential of systemic administration of pluripotent bone marrow-derived mesenchymal stem cells (MSCs to rescue vision and associated vascular pathology in the Royal College Surgeons (RCS rat, a well-established animal model for RP. METHODOLOGY/PRINCIPAL FINDINGS: Animals received syngeneic MSCs (1x10(6 cells by tail vein at an age before major photoreceptor loss. PRINCIPAL RESULTS: both rod and cone photoreceptors were preserved (5-6 cells thick at the time when control animal has a single layer of photoreceptors remained; Visual function was significantly preserved compared with controls as determined by visual acuity and luminance threshold recording from the superior colliculus; The number of pathological vascular complexes (abnormal vessels associated with migrating pigment epithelium cells and area of vascular leakage that would ordinarily develop were dramatically reduced; Semi-quantitative RT-PCR analysis indicated there was upregulation of growth factors and immunohistochemistry revealed that there was an increase in neurotrophic factors within eyes of animals that received MSCs. CONCLUSIONS/SIGNIFICANCE: These results underscore the potential application of MSCs in treating retinal degeneration. The advantages of this non-invasive cell-based therapy are: cells are easily isolated and can be expanded in large quantity for autologous graft; hypoimmunogenic nature as allogeneic donors; less controversial in nature than other stem cells; can be readministered with minor discomfort

Retinitispigmentosa (RP) is a highly heterogeneous genetic disease. The USH2A gene, which accounts for approximately 74-90% of Usher syndrome type 2 (USH2) cases, is also one of the major autosomal recessive RP (arRP) causative genes among Caucasian populations. To identify disease-causing USH2A gene mutations in Japanese RP patients, all 73 exons were screened for mutations by direct sequencing. In total, 100 unrelated Japanese RP patients with no systemic manifestations were identified, excluding families with obvious autosomal dominant inheritance. Of these 100 patients, 82 were included in this present study after 18 RP patients with very likely pathogenic EYS (eyes shut homolog) mutations were excluded. The mutation analysis of the USH2A revealed five very likely pathogenic mutations in four patients. A patient had only one very likely pathogenic mutation and the others had two of them. Caucasian frequent mutations p.C759F in arRP and p.E767fs in USH2 were not found. All the four patients exhibited typical clinical features of RP. The observed prevalence of USH2A gene mutations was approximately 4% among Japanese arRP patients, and the profile of the USH2A gene mutations differed largely between Japanese patients and previously reported Caucasian populations.

We reviewed and illustrated the most optimal retinal structural measurements to make in stem cell clinical trials. Optical coherence tomography (OCT) and autofluorescence (AF) imaging were used to evaluate patients with severe visual loss from nonsyndromic and syndromic retinitispigmentosa (RP), ABCA4-Stargardt disease, and nonneovascular age-related macular degeneration (AMD). Outer nuclear layer (ONL), rod outer segment (ROS) layer, inner retina, ganglion cell layer (GCL), and nerve fiber layer (NFL) thicknesses were quantified. All patients had severely reduced visual acuities. Retinitispigmentosa patients had limited visual fields; maculopathy patients had central scotomas with retained peripheral function. For the forms of RP illustrated, there was detectable albeit severely reduced ONL across the scanned retina, and normal or hyperthick GCL and NFL. Maculopathy patients had no measurable ONL centrally; it became detectable with eccentricity. Some maculopathy patients showed unexpected GCL losses. Autofluorescence imaging illustrated central losses of RPE integrity. A hypothetical scheme to relate patient data with different phases of retinal remodeling in animal models of retinal degeneration was presented. Stem cell science is advancing, but it is not too early to open the discussion of criteria for patient selection and monitoring. Available clinical tools, such as OCT and AF imaging, can provide inclusion/exclusion criteria and robust objective outcomes. Accepting that early trials may not lead to miraculous cures, we should be prepared to know why-scientifically and clinically-so we can improve subsequent trials. We also must determine if retinal remodeling is an impediment to efficacy.

An electronic retinal prosthesis is under development to treat retinitispigmentosa and age-related macular degeneration, two presently incurable diseases of the outer retina that afflict millions world-wide...

Full Text Available Purpose. To explore functional electroretinographic (ERG changes and associated cellular remodeling following experimental retinal detachment in a rabbit model. Methods. Retinal detachment was created in ten rabbits by injecting 0.1 ml balanced salt solution under the retina. Fundus imaging was performed 0, 3, 7, 14, and 21 days postoperatively. ERGs were recorded pre- and 7 and 21 days postoperatively. Eyes were harvested on day 21 and evaluated immunohistochemically (IHC for remodeling of second- and third-order neurons. Results. Retinal reattachment occurred within two weeks following surgery. No attenuation was observed in the photopic or scotopic a- and b-waves. A secondary wavefront on the descending slope of the scotopic b-wave was the only ERG result that was attenuated in detached retinas. IHC demonstrated anatomical changes in both ON and OFF bipolar cells. Bassoon staining was observed in the remodeled dendrites. Amacrine and horizontal cells did not alter, but Muller cells were clearly reactive with marked extension. Conclusion. Retinal detachment and reattachment were associated with functional and anatomical changes. Exploring the significance of the secondary scotopic wavefront and its association with the remodeling of 2nd- and 3rd-order neurons will shade more light on functional changes and recovery of the retina.

Full Text Available Development of retinal detachment models in small animals can be difficult and expensive. Here we create and characterize a novel, cone-rich retinal detachment (RD model in the chick.Retinal detachments were created in chicks between postnatal days 7 and 21 by subretinal injections of either saline (SA or hyaluronic acid (HA. Injections were performed through a dilated pupil with observation via surgical microscope, using the fellow eye as a control. Immunohistochemical analyses were performed at days 1, 3, 7, 10 and 14 after retinal detachment to evaluate the cellular responses of photoreceptors, Müller glia, microglia and nonastrocytic inner retinal glia (NIRG. Cell proliferation was detected with bromodeoxyuridine (BrdU-incorporation and by the expression of proliferating cell nuclear antigen (PCNA. Cell death was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL. As in mammalian models of RD, there is shortening of photoreceptor outer segments and mis-trafficking of photoreceptor opsins in areas of RD. Photoreceptor cell death was maximal 1 day after RD, but continued until 14 days after RD. Müller glia up-regulated glial fibriliary acidic protein (GFAP, proliferated, showed interkinetic nuclear migration, and migrated to the subretinal space in areas of detachment. Microglia became reactive; they up-regulated CD45, acquired amoeboid morphology, and migrated toward outer retina in areas of RD. Reactive NIRG cells accumulated in detached areas.Subretinal injections of SA or HA in the chick eye successfully produced retinal detachments and cellular responses similar to those seen in standard mammalian models. Given the relatively large eye size, and considering the low cost, the chick model of RD offers advantages for high-throughput studies.

Full Text Available Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (p<0.001 compared to baseline, followed by gradual thinning plateauing two weeks after the experimental intervention (p<0.001. Histological findings at day seven correlated with spectral domain optical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions.

To evaluate a form of nonmendelian inheritance in a patient with retinitispigmentosa (RP). Direct DNA sequencing of the USH2A coding region and microsatellite analysis of polymorphic markers from chromosome 1 and other chromosomes. A patient with RP without hearing loss caused by the homozygous mutation Cys759Phe in the USH2A gene on chromosome 1q was found to be the daughter of a noncarrier mother and a father who was heterozygous for this change. Further evaluation with microsatellite markers revealed that the patient had inherited 2 copies of chromosome 1 from her father and none from her mother. The paternally derived chromosome 1's were heteroallelic from the centromere of chromosome 1 to the proximal short and long arms. The distal regions of the short and long arms of chromosome 1 were homoallelic, including the region of 1q with the mutant USH2A allele. This genetic pattern is compatible with a phenomenon of uniparental primary heterodisomy with regions of homozygosity arising through a nondisjunction event during paternal meiosis I and subsequent trisomy rescue or gamete complementation. A paternal second cousin of the patient also had RP and also had an identical heterozygous mutation in the USH2A gene in the same codon. However, the analysis of an isocoding polymorphism 20 base pairs away and closely linked microsatellite markers in the patient and family members indicated that the 2 mutant alleles are unlikely to be identical by descent and that the 2 relatives fortuitously had RP and a mutation in the same codon of the USH2A gene. This family illustrates that recessive RP without hearing loss can rarely be inherited from only 1 unaffected carrier parent in a nonmendelian manner. The genetic counseling of families with recessively inherited eye diseases must take into consideration the possibility that an unaffected heterozygous carrier can have an affected offspring homozygous for the same mutation, even if the carrier's spouse has wild-type alleles

Retinal degenerative diseases that target photoreceptors or the adjacent retinal pigment epithelium (RPE) affect millions of people worldwide. Retinal degeneration (RD) is found in many different forms of retinal diseases including retinitispigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, cataracts, and glaucoma. Effective treatment for retinal degeneration has been widely investigated. Gene-replacement therapy has been shown to improve visual function in inheri...

Gene therapy is a potentially effective treatment for retinal degenerative diseases. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been developed as a new genome-editing tool in ophthalmic studies. Recent advances in researches showed that CRISPR/Cas9 has been applied in generating animal models as well as gene therapy in vivo of retinitispigmentosa (RP) and leber congenital amaurosis (LCA). It has also been shown as a potential attempt for clinic by combining with other technologies such as adeno-associated virus (AAV) and induced pluripotent stem cells (iPSCs). In this review, we highlight the main points of further prospect of using CRISPR/Cas9 in targeting retinal degeneration. We also emphasize the potential applications of this technique in treating retinal degenerative diseases. PMID:28503441

To develop pharmacokinetics models to describe the disposition of small lipophilic molecules in the cornea and retina after periocular (subconjunctival or posterior subconjunctival) administration. Compartmental pharmacokinetics analysis was performed on the corneal and retinal data obtained after periocular administration of 3 mg of celecoxib (a selective COX-2 inhibitor) to Brown Norway (BN) rats. Berkeley Madonna, a differential and difference equation-based modeling software, was used for the pharmacokinetics modeling. The data were fit to different compartment models with first-order input and disposition, and the best fit was selected on the basis of coefficient of regression and Akaike information criteria (AIC). The models were validated by using the celecoxib data from a prior study in Sprague-Dawley (SD) rats. The corneal model was also fit to the corneal data for prednisolone at a dose of 2.61 mg in albino rabbits, and the model was validated at two other doses of prednisolone (0.261 and 26.1 mg) in these rabbits. Model simulations were performed with the finalized model to understand the effect of formulation on corneal and retinal pharmacokinetics after periocular administration. Celecoxib kinetics in the BN rat cornea can be described by a two-compartment (periocular space and cornea, with a dissolution step for periocular formulation) model, with parallel elimination from the cornea and the periocular space. The inclusion of a distribution compartment or a dissolution step for celecoxib suspension did not lead to an overall improvement in the corneal data fit compared with the two-compartment model. The more important parameter for enhanced fit and explaining the apparent lack of an increase phase in the corneal levels is the inclusion of the initial leak-back of the dose from the periocular space into the precorneal area. The predicted celecoxib concentrations from this model also showed very good correlation (r = 0.99) with the observed values in

Retinal ischemia and pathological angiogenesis cause severe impairment of sight. Oxygen-induced retinopathy (OIR) in young mice is widely used as a model to investigate the underlying pathological mechanisms and develop therapeutic interventions. We compared directly the conventional OIR model (exposure to 75% O2 from postnatal day (P) 7 to P12) with an alternative, accelerated version (85% O2 from P8 to P11). We found that accelerated OIR induces similar pre-retinal neovascularization but greater retinal vascular regression that recovers more rapidly. The extent of retinal gliosis is similar but neuroretinal function, as measured by electroretinography, is better maintained in the accelerated model. We found no systemic or maternal morbidity in either model. Accelerated OIR offers a safe, reliable and more rapid alternative model in which pre-retinal neovascularization is similar but retinal vascular regression is greater.

In lower-order vertebrates, Müller glia exhibit characteristics of retinal progenitor cells, while in higher vertebrates, such as mammals, the regenerative capacity of Müller glia is limited. Recently, we reported that Lin28b promoted the trans-differentiation of Müller cells to rod photoreceptor and bipolar cells in the retina of retinitispigmentosa rat model, whereas it is unclear whether Lin28b can stimulate the reprogramming of Müller glia in vitro for transplantation into a damaged retina. In the present study, Long-Evens rat Müller glia were infected with Adeno-Lin28b or Adeno-GFP. Over-expression of Lin28b in isolated rat Müller glia resulted in the suppression of GFAP expression, enhancement of cell proliferation and a significant increase of the expression of retinal progenitor markers 5 days after infection. Moreover, Lin28b caused a significant reduction of the Let-7 family of microRNAs. Following sub-retinal space transplantation, Müller glia-derived retinal progenitors improved b-wave amplification of 30d Royal College of Surgeons retinitispigmentosamodel (RCS-P+) rats, as detected by electroretinography (ERG) recordings. Taken together, these data suggest that the up-regulation of Lin28b expression facilitated the reprogramming of Müller cells toward characteristics of retinal progenitors. - Highlights: • Lin28b reprograms Müller glia to retinal progenitors. • Let-7 micrRNAs are suppressed by Lin28b. • Transplantation of reprogrammed Müller glia restores retinal function.

In lower-order vertebrates, Müller glia exhibit characteristics of retinal progenitor cells, while in higher vertebrates, such as mammals, the regenerative capacity of Müller glia is limited. Recently, we reported that Lin28b promoted the trans-differentiation of Müller cells to rod photoreceptor and bipolar cells in the retina of retinitispigmentosa rat model, whereas it is unclear whether Lin28b can stimulate the reprogramming of Müller glia in vitro for transplantation into a damaged retina. In the present study, Long-Evens rat Müller glia were infected with Adeno-Lin28b or Adeno-GFP. Over-expression of Lin28b in isolated rat Müller glia resulted in the suppression of GFAP expression, enhancement of cell proliferation and a significant increase of the expression of retinal progenitor markers 5 days after infection. Moreover, Lin28b caused a significant reduction of the Let-7 family of microRNAs. Following sub-retinal space transplantation, Müller glia-derived retinal progenitors improved b-wave amplification of 30d Royal College of Surgeons retinitispigmentosamodel (RCS-P+) rats, as detected by electroretinography (ERG) recordings. Taken together, these data suggest that the up-regulation of Lin28b expression facilitated the reprogramming of Müller cells toward characteristics of retinal progenitors. - Highlights: • Lin28b reprograms Müller glia to retinal progenitors. • Let-7 micrRNAs are suppressed by Lin28b. • Transplantation of reprogrammed Müller glia restores retinal function.

Full Text Available The visual cycle is a sequential enzymatic reaction for vitamin A, all-trans-retinol, occurring in the outer layer of the human retina and is essential for the maintenance of vision. The central source of retinol is derived from dietary intake of both retinol and pro-vitamin A carotenoids. A series of enzymatic reactions, located in both the photoreceptor outer segment and the retinal pigment epithelium, transform retinol into the visual chromophore 11-cis-retinal, regenerating visual pigments. Retina specific proteins carry out the majority of the visual cycle, and any significant interruption in this sequence of reactions is capable of causing varying degrees of blindness. Among these important proteins are Lecithin:retinol acyltransferase (LRAT and retinal pigment epithelium-specific 65-kDa protein (RPE65 known to be responsible for esterification of retinol to all-trans-retinyl esters and isomerization of these esters to 11-cis-retinal, respectively. Deleterious mutations in these genes are identified in human retinal diseases that cause blindness, such as Leber congenital amaurosis (LCA and retinitispigmentosa (RP. Herein, we discuss the pathology of 11-cis-retinal deficiency caused by these mutations in both animal disease models and human patients. We also review novel therapeutic strategies employing artificial visual chromophore 9-cis-retinoids which have been employed in clinical trials involving LCA patients.

Transplant technologies have been studied for the recovery of vision loss from retinitispigmentosa (RP) and age-related macular degeneration (AMD). In several rodent retinal degeneration models and in patients, retinal progenitor cells transplanted as layers to the subretinal space have been shown to restore or preserve vision. The methods for evaluation of transplants are expensive considering the large amount of animals. Alternatively, time-domain Stratus OCT was previously shown to be able to image the morphological structure of transplants to some extent, but could not clearly identify laminated transplants. The efficacy of screening retinal transplants with Fourier-domain OCT was studied on 37 S334ter line 3 rats with retinal degeneration 6-67 days after transplant surgery. The transplants were morphologically categorized as no transplant, detachment, rosettes, small laminated area and larger laminated area with both Fourier-domain OCT and histology. The efficacy of Fourier-domain OCT in screening retinal transplants was evaluated by comparing the categorization results with OCT and histology. Additionally, 4 rats were randomly selected for multiple OCT examinations (1, 5, 9, 14 and 21days post surgery) in order to determine the earliest image time of OCT examination since the transplanted tissue may need some time to show its tendency of growing. Finally, we demonstrated the efficacy of Fourier-domain OCT in screening retinal transplants in early stages and determined the earliest imaging time for OCT. Fourier-domain OCT makes itself valuable in saving resource spent on animals with unsuccessful transplants.

Ischemia-induced hypoxia elicits retinal neovascularization and is a major component of several blinding retinopathies such as retinopathy of prematurity (ROP), diabetic retinopathy (DR) and retinal vein occlusion (RVO). Currently, noninvasive imaging techniques capable of detecting and monitoring retinal hypoxia in living systems do not exist. Such techniques would greatly clarify the role of hypoxia in experimental and human retinal neovascular pathogenesis. In this study, we developed and characterized HYPOX-4, a fluorescence-imaging probe capable of detecting retinal-hypoxia in living animals. HYPOX-4 dependent in vivo and ex vivo imaging of hypoxia was tested in a mouse model of oxygen-induced retinopathy (OIR). Predicted patterns of retinal hypoxia were imaged by HYPOX-4 dependent fluorescence activity in this animal model. In retinal cells and mouse retinal tissue, pimonidazole-adduct immunostaining confirmed the hypoxia selectivity of HYPOX-4. HYPOX-4 had no effect on retinal cell proliferation as indicated by BrdU assay and exhibited no acute toxicity in retinal tissue as indicated by TUNEL assay and electroretinography (ERG) analysis. Therefore, HYPOX-4 could potentially serve as the basis for in vivo fluorescence-based hypoxia-imaging techniques, providing a tool for investigators to understand the pathogenesis of ischemic retinopathies and for physicians to address unmet clinical needs.

Full Text Available Mutations in MYO7A cause autosomal recessive Usher syndrome type IB (USH1B, one of the most frequent conditions that combine severe congenital hearing impairment and retinitispigmentosa. A promising therapeutic strategy for retinitispigmentosa is gene therapy, however its pre-clinical development is limited by the mild retinal phenotype of the shaker1 (sh1(-/- murine model of USH1B which lacks both retinal functional abnormalities and degeneration. Here we report a significant, early-onset delay of sh1(-/- photoreceptor ability to recover from light desensitization as well as a progressive reduction of both b-wave electroretinogram amplitude and light sensitivity, in the absence of significant loss of photoreceptors up to 12 months of age. We additionally show that subretinal delivery to the sh1(-/- retina of AAV vectors encoding the large MYO7A protein results in significant improvement of sh1(-/- photoreceptor and retinal pigment epithelium ultrastructural anomalies which is associated with improvement of recovery from light desensitization. These findings provide new tools to evaluate the efficacy of experimental therapies for USH1B. In addition, although AAV vectors expressing large genes might have limited clinical applications due to their genome heterogeneity, our data show that AAV-mediated MYO7A gene transfer to the sh1(-/- retina is effective.

Photoreceptors degenerate in a wide array of hereditary retinal diseases and age-related macular degeneration. There is currently no treatment available for retinal degenerations. While outnumbered roughly 20:1 by rods in the human retina, it is the cones that mediate color vision and visual acuity, and their survival is critical for vision. In this communication, we investigate whether thyroid hormone (TH) signaling affects cone viability in retinal degeneration mouse models. TH signaling is...

Vertebrate vision is initiated by photoisomerization of the visual pigment chromophore 11-cis-retinal and is maintained by continuous regeneration of this retinoid through a series of reactions termed the retinoid cycle. However, toxic side reaction products, especially those involving reactive aldehyde groups of the photoisomerized product, all-trans-retinal, can cause severe retinal pathology. Here we lowered peak concentrations of free all-trans-retinal with primary amine-containing Food and Drug Administration (FDA)-approved drugs that did not inhibit chromophore regeneration in mouse models of retinal degeneration. Schiff base adducts between all-trans-retinal and these amines were identified by MS. Adducts were observed in mouse eyes only when an experimental drug protected the retina from degeneration in both short-term and long-term treatment experiments. This study demonstrates a molecular basis of all-trans-retinal-induced retinal pathology and identifies an assemblage of FDA-approved compounds with protective effects against this pathology in a mouse model that shows features of Stargardt's disease and age-related retinal degeneration.

Fundus autofluorescence (fundus AF) changes were monitored in a mouse model of retinal detachment (RD). RD was induced by transscleral injection of hyaluronic acid (Healon) or sterile balanced salt solution (BSS) into the subretinal space of 4-5-day-old albino Abca4 null mutant and Abca4 wild-type mice. Images acquired by confocal scanning laser ophthalmoscopy (Spectralis HRA) were correlated with spectral domain optical coherence tomography (SD-OCT), infrared reflectance (IR), fluorescence spectroscopy, and histologic analysis. Results. In the area of detached retina, multiple hyperreflective spots in IR images corresponded to punctate areas of intense autofluorescence visible in fundus AF mode. The puncta exhibited changes in fluorescence intensity with time. SD-OCT disclosed undulations of the neural retina and hyperreflectivity of the photoreceptor layer that likely corresponded to histologically visible photoreceptor cell rosettes. Fluorescence emission spectra generated using flat-mounted retina, and 488 and 561 nm excitation, were similar to that of RPE lipofuscin. With increased excitation wavelength, the emission maximum shifted towards longer wavelengths, a characteristic typical of fundus autofluorescence. In detached retinas, hyper-autofluorescent spots appeared to originate from photoreceptor outer segments that were arranged within retinal folds and rosettes. Consistent with this interpretation is the finding that the autofluorescence was spectroscopically similar to the bisretinoids that constitute RPE lipofuscin. Under the conditions of a RD, abnormal autofluorescence may arise from excessive production of bisretinoid by impaired photoreceptor cells.

In this work various methods of parametric elastic models are compared, namely the classical snake, the gradient vector field snake (GVF snake) and the topology-adaptive snake (t-snake), as well as the method of self-affine mapping system as an alternative to elastic models. We also give a brief overview of the methods used. The self-affine mapping system is implemented using an adapting scheme and minimum distance as optimization criterion, which is more suitable for weak edges detection. All methods are applied to glaucomatic retinal images with the purpose of segmenting the optical disk. The methods are compared in terms of segmentation accuracy and speed, as these are derived from cross-correlation coefficients between real and algorithm extracted contours and segmentation time, respectively. As a result, the method of self-affine mapping system presents adequate segmentation time and segmentation accuracy, and significant independence from initialization.

PURPOSE: Glucose concentrations are elevated in retinal cells in undiagnosed and in undertreated diabetes. Studies of diabetic patients suggest that retinal function adapts, to some extent, to this increased supply of glucose. The aim of the present study was to examine such adaptation in a model...

Full Text Available AIM:To develop a reliable, reproducible rat model of retinal vein occlusion (RVO with a novel photosensitizer (erythrosin B and study the cellular responses in the retina.METHODS:Central and branch RVOs were created in adult male rats via photochemically-induced ischemia. Retinal changes were monitored via color fundus photography and fluorescein angiography at 1 and 3h, and 1, 4, 7, 14, and 21d after irradiation. Tissue slices were evaluated histopathologically. Retinal ganglion cell survival at different times after RVO induction was quantified by nuclear density count. Retinal thickness was also observed.RESULTS:For all rats in both the central and branch RVO groups, blood flow ceased immediately after laser irradiation and retinal edema was evident at one hour. The retinal detachment rate was 100% at 3h and developed into bullous retinal detachment within 24h. Retinal hemorrhages were not observed until 24h. Clearance of the occluded veins at 7d was observed by fluorescein angiography. Disease manifestation in the central RVO eyes was more severe than in the branch RVO group. A remarkable reduction in the ganglion cell count and retinal thickness was observed in the central RVO group by 21d, whereas moderate changes occurred in the branch RVO group.CONCLUSION: Rat RVO created by photochemically-induced ischemia using erythrosin B is a reproducible and reliable animal model for mimicking the key features of human RVO. However, considering the 100% rate of retinal detachment, this animal model is more suitable for studying RVO with chronic retinal detachment.

Retinal diseases such as age-related macular degeneration and retinitispigmentosa remain major causes of severe vision loss in humans. Clinical trials for treatment of retinal degenerations are underway and advancements in our understanding of retinal biology in health/disease have implications for novel therapies. A review of retinal biology is used to inform a discussion of current strategies to maintain/repair neural circuitry in age-related macular degeneration, retinitispigmentosa, and Type 2 Leber congenital amaurosis. In age-related macular degeneration/retinitispigmentosa, a progressive loss of rods/cones results in corruption of bipolar cell circuitry, although retinal output neurons/photoreceptive melanopsin cells survive. Visual function can be stabilized/enhanced after treatment in age-related macular degeneration, but in advanced degenerations, reorganization of retinal circuitry may preclude attempts to restore cone function. In Type 2 Leber congenital amaurosis, useful vision can be restored by gene therapy where central cones survive. Remarkable progress has been made in restoring vision to rodents using light-responsive ion channels inserted into bipolar cells/retinal ganglion cells. Advances in genetic, cellular, and prosthetic therapies show varying degrees of promise for treating retinal degenerations. While functional benefits can be obtained after early therapeutic interventions, efforts should be made to minimize circuitry changes as soon as possible after rod/cone loss. Advances in retinal anatomy/physiology and genetic technologies should allow refinement of future reparative strategies.

Full Text Available Experimental models of diabetic retinopathy (DR have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight.

Usher syndrome is a group of diseases with autosomal recessive inheritance, congenital hearing loss, and the development of retinitispigmentosa, a progressive retinal degeneration characterized by night blindness and visual field loss over several decades. The causes of Usher syndrome are unknown and no animal models have been available for study. Four human gene sites have been reported, suggesting at least four separate forms of Usher syndrome. We report a mouse model of type I Usher syndr...

Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitispigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases. PMID:25650393

Full Text Available Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases.

Retinal ischemia is a common cause of visual impairment for humans and animals. Herein, the neuroprotective effects of phenylbutyrate (PBA) upon retinal ischemic injury were investigated using a rat model. Retinal ganglion cells (RGCs) were retrograde labeled with the fluorescent tracer fluorogold (FG) applied to the superior collicoli of test Sprague-Dawley rats. High intraocular pressure and retinal ischemia were induced seven days subsequent to such FG labeling. A dose of either 100 or 400 mg/kg PBA was administered intraperitoneally to test rats at two time points, namely 30 min prior to the induction of retinal ischemia and 1 h subsequent to the cessation of the procedure inducing retinal ischemia. The test-rat retinas were collected seven days subsequent to the induction of retinal ischemia, and densities of surviving RGCs were estimated by counting FG-labeled RGCs within the retina. Histological analysis revealed that ischemic injury caused the loss of retinal RGCs and a net decrease in retinal thickness. For PBA-treated groups, almost 100% of the RGCs were preserved by a pre-ischemia treatment with PBA (at a dose of either 100 or 400 mg/kg), while post-ischemia treatment of RGCs with PBA did not lead to the preservation of RGCs from ischemic injury by PBA as determined by the counting of whole-mount retinas. Pre-ischemia treatment of RGCs with PBA (at a dose of either 100 or 400 mg/kg) significantly reduced the level of ischemia-associated loss of thickness of the total retina, especially the inner retina, and the inner plexiform layer of retina. Besides, PBA treatment significantly reduced the ischemia-induced loss of cells in the ganglion-cell layer of the retina. Taken together, these results suggest that PBA demonstrates a marked neuroprotective effect upon high intraocular pressure-induced retinal ischemia when the PBA is administered prior to ischemia induction.

Full Text Available Abstract Background Drusen are common features in the ageing macula associated with exudative Age-Related Macular Degeneration (ARMD. They are visible in retinal images and their quantitative analysis is important in the follow up of the ARMD. However, their evaluation is fastidious and difficult to reproduce when performed manually. Methods This article proposes a methodology for Automatic Drusen Deposits Detection and quantification in Retinal Images (AD3RI by using digital image processing techniques. It includes an image pre-processing method to correct the uneven illumination and to normalize the intensity contrast with smoothing splines. The drusen detection uses a gradient based segmentation algorithm that isolates drusen and provides basic drusen characterization to the modelling stage. The detected drusen are then fitted by Modified Gaussian functions, producing a model of the image that is used to evaluate the affected area. Twenty two images were graded by eight experts, with the aid of a custom made software and compared with AD3RI. This comparison was based both on the total area and on the pixel-to-pixel analysis. The coefficient of variation, the intraclass correlation coefficient, the sensitivity, the specificity and the kappa coefficient were calculated. Results The ground truth used in this study was the experts' average grading. In order to evaluate the proposed methodology three indicators were defined: AD3RI compared to the ground truth (A2G; each expert compared to the other experts (E2E and a standard Global Threshold method compared to the ground truth (T2G. The results obtained for the three indicators, A2G, E2E and T2G, were: coefficient of variation 28.8 %, 22.5 % and 41.1 %, intraclass correlation coefficient 0.92, 0.88 and 0.67, sensitivity 0.68, 0.67 and 0.74, specificity 0.96, 0.97 and 0.94, and kappa coefficient 0.58, 0.60 and 0.49, respectively. Conclusions The gradings produced by AD3RI obtained an agreement

After decades of basic science research involving the testing of regenerative strategies in animal models of retinal degenerative diseases, a number of clinical trials are now underway, with additional trials set to begin shortly. These efforts will evaluate the safety and preliminary efficacy of cell-based products in the eyes of patients with a number of retinal conditions, notably including age-related macular degeneration, retinitispigmentosa and Stargardt's disease. This review considers the scientific work and early trials with fetal cells and tissues that set the stage for the current clinical investigatory work, as well the trials themselves, specifically those either now completed, underway or close to initiation. The cells of interest include retinal pigment epithelial cells derived from embryonic stem or induced pluripotent stem cells, undifferentiated neural or retinal progenitors or cells from the vascular/bone marrow compartment or umbilical cord tissue. Degenerative diseases of the retina represent a popular target for emerging cell-based therapeutics and initial data from early stage clinical trials suggest that short-term safety objectives can be met in at least some cases. The question of efficacy will require additional time and testing to be adequately resolved.

Full Text Available Purpose: The P23H rhodopsin mutation is an autosomal dominant cause of retinitispigmentosa. The degeneration can be tracked using different anatomical and functional methods. In our case, we evaluated the anatomical changes using Spectral-Domain Optical Coherence Tomography (SD-OCT and correlated the findings with retinal thickness values determined by immunocytochemistry.Methods: Pigmented rats heterozygous for the P23H mutation, with ages between P18 and P180 were studied. Function was assessed by means of optomotor testing and ERGs. Retinal thicknesses measurements, autofluorescence and fluorescein angiography were performed using Spectralis OCT. Retinas were studied by means of immunohistochemistry. Results: Between P30 and P180, visual acuity decreased from 0.500 to 0.182 cycles per degree (cyc/deg and contrast sensitivity decreased from 54.56 to 2.98 for a spatial frequency of 0.089 cyc/deg. Only cone-driven b-wave responses reached developmental maturity. Flicker fusions were also comparable at P29 (42 Hz. Double flash-isolated rod-driven responses were already affected at P29. Photopic responses revealed deterioration after P29.A reduction in retinal thicknesses and morphological modifications were seen in OCT sections. Statistically significant differences were found in all evaluated thicknesses. Autofluorescence was seen in P23H rats as sparse dots. Immunocytochemistry showed a progressive decrease in the outer nuclear layer, and morphological changes. Although anatomical thickness measures were significantly lower than OCT values, there was a very strong correlation between the values measured by both techniques.Conclusions: In pigmented P23H rats, a progressive deterioration occurs in both retinal function and anatomy. Anatomical changes can be effectively evaluated using SD-OCT and immunocytochemistry, with a good correlation between their values, thus making SD-OCT an important tool for research in retinal degeneration.

Accurate edge detection of retinal vessels is a prerequisite for quantitative analysis of subtle morphological changes of retinal vessels under different pathological conditions. A novel method for edge detection of retinal vessels is presented in this paper. Methods: (1) Wavelet-based image preprocessing. (2) The signed edge detection algorithm and mathematical morphological operation are applied to get the approximate regions that contain retinal vessels. (3) By convolving the preprocessed image with a LoG operator only on the detected approximate regions of retinal vessels, followed by edges refining, clear edge maps of the retinal vessels are fast obtained. Results: A detailed performance evaluation together with the existing techniques is given to demonstrate the strong features of our method. Conclusions: True edge locations of retinal vessels can be fast detected with continuous structures of retinal vessels, less non- vessel segments left and insensitivity to noise. The method is also suitable for other application fields such as road edge detection.

Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitispigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

Full Text Available Retinitispigmentosa (RP is the most common inherited human eye disease resulting in night blindness and visual defects. It is well known that the disease is caused by rod photoreceptor degeneration; however, it remains incurable, due to the unavailability of disease-specific human photoreceptor cells for use in mechanistic studies and drug screening. We obtained fibroblast cells from five RP patients with distinct mutations in the RP1, RP9, PRPH2 or RHO gene, and generated patient-specific induced pluripotent stem (iPS cells by ectopic expression of four key reprogramming factors. We differentiated the iPS cells into rod photoreceptor cells, which had been lost in the patients, and found that they exhibited suitable immunocytochemical features and electrophysiological properties. Interestingly, the number of the patient-derived rod cells with distinct mutations decreased in vitro; cells derived from patients with a specific mutation expressed markers for oxidation or endoplasmic reticulum stress, and exhibited different responses to vitamin E than had been observed in clinical trials. Overall, patient-derived rod cells recapitulated the disease phenotype and expressed markers of cellular stresses. Our results demonstrate that the use of patient-derived iPS cells will help to elucidate the pathogenic mechanisms caused by genetic mutations in RP.

Full Text Available In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modelingretinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

Full Text Available Retinitispigmentosa (RP is one of the most common retinal degenerative conditions affecting people worldwide, and is currently incurable. It is characterized by the progressive loss of photoreceptors, in which the death of rod cells leads to the secondary death of cone cells; the cause of eventual blindness. As rod cells die, retinal-oxygen metabolism becomes perturbed, leading to increased levels of reactive oxygen species (ROS and thus oxidative stress; a key factor in the secondary death of cones. In this study, norgestrel, an FDA-approved synthetic analog of progesterone, was found to be a powerful neuroprotective antioxidant, preventing light-induced ROS in photoreceptor cells, and subsequent cell death. Norgestrel also prevented light-induced photoreceptor morphological changes that were associated with ROS production, and that are characteristic of RP. Further investigation showed that norgestrel acts via post-translational modulation of the major antioxidant transcription factor Nrf2; bringing about its phosphorylation, subsequent nuclear translocation, and increased levels of its effector protein superoxide dismutase 2 (SOD2. In summary, these results demonstrate significant protection of photoreceptor cells from oxidative stress, and underscore the potential of norgestrel as a therapeutic option for RP.

Retinal prosthesis offers a potential treatment for individuals suffering from photoreceptor degeneration diseases. Establishing biological retinalmodels and simulating how the biological retina convert incoming light signal into spike trains that can be properly decoded by the brain is a key issue. Some retinalmodels have been presented, ranking from structural models inspired by the layered architecture to functional models originated from a set of specific physiological phenomena. However, Most of these focus on stimulus image compression, edge detection and reconstruction, but do not generate spike trains corresponding to visual image. In this study, based on state-of-the-art retinal physiological mechanism, including effective visual information extraction, static nonlinear rectification of biological systems and neurons Poisson coding, a cascade model of the retina including the out plexiform layer for information processing and the inner plexiform layer for information encoding was brought forward, which integrates both anatomic connections and functional computations of retina. Using MATLAB software, spike trains corresponding to stimulus image were numerically computed by four steps: linear spatiotemporal filtering, static nonlinear rectification, radial sampling and then Poisson spike generation. The simulated results suggested that such a cascade model could recreate visual information processing and encoding functionalities of the retina, which is helpful in developing artificial retina for the retinally blind.

Full Text Available Retinal degeneration arises from the loss of photoreceptors or retinal pigment epithelium (RPE. It is one of the leading causes of irreversible blindness worldwide with limited effective treatment options. Generation of induced pluripotent stem cell (IPSC-derived retinal cells and tissues from individuals with retinal degeneration is a rapidly evolving technology that holds a great potential for its use in disease modelling. IPSCs provide an ideal platform to investigate normal and pathological retinogenesis, but also deliver a valuable source of retinal cell types for drug screening and cell therapy. In this review, we will provide some examples of the ways in which IPSCs have been used to model diseases of the outer retina including retinitispigmentosa (RP, Usher syndrome (USH, Leber congenital amaurosis (LCA, gyrate atrophy (GA, juvenile neuronal ceroid lipofuscinosis (NCL, Best vitelliform macular dystrophy (BVMD and age related macular degeneration (AMD.

Retinal degeneration arises from the loss of photoreceptors or retinal pigment epithelium (RPE). It is one of the leading causes of irreversible blindness worldwide with limited effective treatment options. Generation of induced pluripotent stem cell (IPSC)-derived retinal cells and tissues from individuals with retinal degeneration is a rapidly evolving technology that holds a great potential for its use in disease modelling. IPSCs provide an ideal platform to investigate normal and pathological retinogenesis, but also deliver a valuable source of retinal cell types for drug screening and cell therapy. In this review, we will provide some examples of the ways in which IPSCs have been used to model diseases of the outer retina including retinitispigmentosa (RP), Usher syndrome (USH), Leber congenital amaurosis (LCA), gyrate atrophy (GA), juvenile neuronal ceroid lipofuscinosis (NCL), Best vitelliform macular dystrophy (BVMD) and age related macular degeneration (AMD).

Purpose To investigate the feasibility of bypassing occluded segments of retinal venous main vessels in isolated, arterially perfused caprine eyes via the closed-sky vitrectomy approach using keratoprosthesis. Methods Isolated caprine eyes were used in this study. For each eye, the retinal vessel was perfused by Krebs solution via ophthalmic artery, and pars plana vitrectomy was performed using temporary keratoprosthesis. All retinal micro-vascular maneuvers were performed in a closed-sky eyeball. The main retinal vein was blocked by endodiathermy at the site of the vessel's first branching. Two openings, several millimeters apart, were created by vascular punctures in both the main vein and its branch vein wall straddling the induced occluded segment. Catheterization was achieved using a flexible polyimide tube, with each end inserted into the vessel wall opening. A sealed connection between the vessel and the tube was obtained by endodiathermy. Bypass of the occluded retinal vein segment was thus achieved, and the patency of this vascular bypass was confirmed by intravascular staining. Results Puncturing, catheterization, and endodiathermy were viable by closed-sky approach using keratoprosthesis. Bypassing of the occluded retinal main vein segment was accomplished with the combination of these maneuvers. Good results were obtained in 23 of 38 (60%) caprine eyes. Conclusions This study demonstrated that bypassing the occluded segment of retinal main vein can be successfully performed in a closed-sky eyeball model of isolated, arterially perfused caprine eye. This early work indicated that the more advanced retinal vascular bypass surgery in in vivo eye may be feasible in the future. PMID:21921946

Highlights: •Aberrant activation of HIF pathway is the underlying cause of ischemic neovascularization. •Honokiol has better therapeutic index as a HIF inhibitor than digoxin and doxorubicin. •Daily IP injection of honokiol in OIR mouse model reduced retinal neovascularization. •Honokiol also prevents vaso-obliteration, the characteristic feature of the OIR model. •Honokiol enhanced physiological revascularization of the retinal vascular plexuses. -- Abstract: Aberrant activation of the hypoxia inducible factor (HIF) pathway is the underlying cause of retinal neovascularization, one of the most common causes of blindness worldwide. The HIF pathway also plays critical roles during tumor angiogenesis and cancer stem cell transformation. We have recently shown that honokiol is a potent inhibitor of the HIF pathway in a number of cancer and retinal pigment epithelial cell lines. Here we evaluate the safety and efficacy of honokiol, digoxin, and doxorubicin, three recently identified HIF inhibitors from natural sources. Our studies show that honokiol has a better safety to efficacy profile as a HIF inhibitor than digoxin and doxorubicin. Further, we show for the first time that daily intraperitoneal injection of honokiol starting at postnatal day (P) 12 in an oxygen-induced retinopathy (OIR) mouse model significantly reduced retinal neovascularization at P17. Administration of honokiol also prevents the oxygen-induced central retinal vaso-obliteration, characteristic feature of the OIR model. Additionally, honokiol enhanced physiological revascularization of the retinal vascular plexuses. Since honokiol suppresses multiple pathways activated by HIF, in addition to the VEGF signaling, it may provide advantages over current treatments utilizing specific VEGF antagonists for ocular neovascular diseases and cancers.

of this study was to examine the prevalence and diagnostic spectrum of generalized retinal dystrophy in the Danish population. METHODS: A population-based cross-sectional study with data from the Danish RetinitisPigmentosa Registry that comprises all patients in Denmark with generalized retinal......PURPOSE: Generalized retinal dystrophy is a frequent cause of visual impairment and blindness in younger individuals and a subject of new clinical intervention trials. Nonetheless, there are few nation-wide population-based epidemiological data of generalized retinal dystrophy. The purpose...... and chorioretinal dystrophies from the 19th century to the present. Among 3076 registered cases, the primary diagnosis of generalized retinal dystrophy was assessed by chart review, including fundus photographs and electroretinograms. Demographic data on the Danish population were retrieved from Statistics Denmark...

Retinopathy of prematurity, formerly known as a retrolental fibroplasia, is a leading cause of infantile blindness worldwide. Retinopathy of prematurity is caused by the failure of central retinal vessels to reach the retinal periphery, creating a nonperfused peripheral retina, resulting in retinal hypoxia, neovascularization, vitreous hemorrhage, vitreoretinal fibrosis, and loss of vision. We established a potential retinopathy of prematurity model by using a green fluorescent vascular endothelium zebrafish transgenic line treated with cobalt chloride (a hypoxia-inducing agent), followed by GS4012 (a vascular endothelial growth factor inducer) at 24 hours postfertilization, and observed that the number of vascular branches and sprouts significantly increased in the central retinal vascular trunks 2-4 days after treatment. We created an angiography method by using tetramethylrhodamine dextran, which exhibited severe vascular leakage through the vessel wall into the surrounding retinal tissues. The quantification of mRNA extracted from the heads of the larvae by using real-time quantitative polymerase chain reaction revealed a twofold increase in vegfaa and vegfr2 expression compared with the control group, indicating increased vascular endothelial growth factor signaling in the hypoxic condition. In addition, we demonstrated that the hypoxic insult could be effectively rescued by several antivascular endothelial growth factor agents such as SU5416, bevacizumab, and ranibizumab. In conclusion, we provide a simple, highly reproducible, and clinically relevant retinopathy of prematurity model based on zebrafish embryos; this model may serve as a useful platform for clarifying the mechanisms of human retinopathy of prematurity and its progression.

The use of canine models of retinal disease in the development of therapeutic strategies for inherited retinal disorders is a growing area of research. To evaluate accurately the success of potential vision-enhancing treatments, reliable methods for objectively assessing visual function in canine models is necessary. A simple vision-testing device was constructed that consisted of a junction box with four exit tunnels. Dogs were placed in the junction box and given one vision-based choice for exit. The first-choice tunnel and time to exit were recorded and analyzed. Two canine models of retinal disease with distinct molecular defects, a null mutation in the gene encoding the alpha subunit of rod cyclic GMP phosphodiesterase (PDE6A), and a null mutation in the gene encoding a retinal pigment epithelium-specific protein (RPE65) were tested and compared to those in unaffected dogs. With the use of bright light versus dim red light, the test differentiated between unaffected dogs and dogs affected with either mutation with a high degree of certainty. The white-light intensity series showed a significantly different performance between the unaffected and affected dogs. A significant difference in performance was detected between the dogs with each mutation. The results indicate that this novel canine vision-testing method is an accurate and sensitive means of distinguishing between unaffected dogs and dogs affected with two different forms of inherited retinal disease and should be useful as a means of assessing response to therapy in future studies.

Pharmacotherapy with visual cycle modulators (VCMs) is under investigation for retinitispigmentosa (RP), Leber congenital amaurosis (LCA), Stargardt macular dystrophy (SMD) and nonexudative age-related macular degeneration (AMD), all blinding diseases that lack effective treatment options. Areas covered: The authors review investigational VCMs, including oral retinoids, 9-cis-retinyl-acetate (zuretinol) and 9-cis-β-carotene, which restore 11-cis-retinal levels in RP and LCA caused by LRAT and RPE65 gene mutations, and may improve visual acuity and visual fields. Therapies for SMD aiming to decrease accumulation of toxic Vitamin A dimers and lipofuscin in the retina and retinal pigment epithelium (RPE) include C20-D3-vitamin A (ALK-001), isotretinoin, VM200, emixustat, and A1120. Mouse models of SMD show promising data for these treatments, though proof of efficacy in humans is currently lacking. Fenretinide and emixustat are investigational VCMs for dry AMD, though neither has been shown to reduce geographic atrophy or improve vision in human trials. A1120 prevents retinol transport into the RPE and may spare the side effects typically seen in VCMs (nyctalopia and chromatopsia) per mouse studies. Expert opinion: Oral VCMs may be feasible treatment options for degenerative retinal diseases based on pre-clinical and some early clinical studies. Further trials are warranted to assess their efficacy and safety in humans.

This study tested the Ins2(Akita) mouse as an animal model of retinal complications in diabetes. The Ins2(Akita) mutation results in a single amino acid substitution in the insulin 2 gene that causes misfolding of the insulin protein. The mutation arose and is maintained on the C57BL/6J background. Male mice heterozygous for this mutation have progressive loss of beta-cell function, decreased pancreatic beta-cell density, and significant hyperglycemia, as early as 4 weeks of age. Heterozygous Ins2(Akita) mice were bred to C57BL/6J mice, and male offspring were monitored for hyperglycemia, beginning at 4.5 weeks of age. After 4 to 36 weeks of hyperglycemia, the retinas were analyzed for vascular permeability, vascular lesions, leukostasis, morphologic changes of micro- and macroglia, apoptosis, retinal degeneration, and insulin receptor kinase activity. The mean blood glucose of Ins2(Akita) mice was significantly elevated, whereas the body weight at death was reduced compared with that of control animals. Compared with sibling control mice, the Ins2(Akita) mice had increased retinal vascular permeability after 12 weeks of hyperglycemia (P microglia, but no changes in expression of Muller cell glial fibrillary acidic protein. Increased apoptosis was identified by immunoreactivity for active caspase-3 after 4 weeks of hyperglycemia (P cell bodies in the retinal ganglion cell layer (P retinal complications of diabetes.

Full Text Available Examination of the response of the retinal proteome to elevated intraocular pressure (IOP and to the pharmacological normalization of IOP is crucial, in order to develop drugs with neuroptorective potential. We used a hereditary rat model of ocular hypertension to lower IOP with travaprost and dorzolamide applied topically on the eye surface, and examine changes of the retinal proteome. Our data demonstrate that elevated IOP causes alterations in the retinal protein profile, in particular in high-mobility-group-protein B1 (HMGB1, calmodulin, heat-shock-protein (HSP 70 and carbonic anhydrase II expression. The changes of the retinal proteome by dorzolamide or travoprost are different and independent of the IOP lowering effect. This fact suggests that the eye drops exert a direct IOP-independent effect on retinal metabolism. Further investigations are required to elucidate the potential neuroprotective mechanisms signaled through changes of HMGB1, calmodulin, HSP70 and carbonic anhydrase II expression in glaucoma. The data may facilitate development of eye drops that exert neuroprotection through direct pharmacological effect.

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is necessary for photoreceptors to generate an important lipid component of their membranes. The absence of LPCAT1 results in early and rapid rod and cone degeneration. Retinal degeneration 11 (rd11) mice carry a mutation in the Lpcat1 gene, and are an excellent model of early-onset rapid retinal degeneration (RD). To date, no reports have documented gene therapy administration in the rd11 mouse model at different ages. In this study, the AAV8 (Y733F)-smCBA-Lpcat1 vector was subretinally injected at postnatal day (P) 10, 14, 18, or 22. Four months after injection, immunohistochemistry and analysis of retinal morphology showed that treatment at P10 rescued about 82% of the wild-type retinal thickness. However, the diffusion of the vector and the resulting rescue were limited to an area around the injection site that was only 31% of the total retinal area. Injection at P14 resulted in vector diffusion that covered approximately 84% of the retina, and we found that gene therapy was more effective against RD when exposure to light was limited before and after treatment. We observed long-term preservation of electroretinogram (ERG) responses, and preservation of retinal structure, indicating that early treatment followed by limited light exposure can improve gene therapy effectiveness for the eyes of rd11 mice. Importantly, delayed treatment still partially preserved M-cones, but not S-cones, and M-cones in the rd11 retina appeared to have a longer window of opportunity for effective preservation with gene therapy. These results provide important information regarding the effects of subretinal gene therapy in the mouse model of LPCAT1-deficiency.

Diabetic Retinopathy is one of the leading causes of blindness and vision defects in developed countries. An early detection and diagnosis is crucial to avoid visual complication. Microaneurysms are the first ocular signs of the presence of this ocular disease. Their detection is of paramount importance for the development of a computer-aided diagnosis technique which permits a prompt diagnosis of the disease. However, the detection of microaneurysms in retinal images is a difficult task due to the wide variability that these images usually present in screening programs. We propose a statistical approach based on mixture model-based clustering and logistic regression which is robust to the changes in the appearance of retinal fundus images. The method is evaluated on the public database proposed by the Retinal Online Challenge in order to obtain an objective performance measure and to allow a comparative study with other proposed algorithms.

Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness. The optic nerve crush (ONC) injury mouse model is an important experimental disease model for traumatic optic neuropathy, glaucoma, etc. In this model, the crush injury to the optic nerve leads to gradual retinal ganglion cells apoptosis. This disease model can be used to study the general processes and mechanisms of neuronal death and survival, which is essential for the development of therapeutic measures. In addition, pharmacological and molecular approaches can be used in this model to identify and test potential therapeutic reagents to treat different types of optic neuropathy. Here, we provide a step by step demonstration of (I) Baseline retrograde labeling of retinal ganglion cells (RGCs) at day 1, (II) Optic nerve crush injury at day 4, (III) Harvest the retinae and analyze RGC survival at day 11, and (IV) Representative result. PMID:21540827

Mutations in the CRB1 gene lead to retinal dystrophies ranging from Leber congenital amaurosis (LCA) to early-onset retinitispigmentosa (RP), due to developmental defects or loss of adhesion between photoreceptors and Muller glia cells, respectively. Whereas over 150 mutations have been found, no

Mutations in the CRB1 gene lead to retinal dystrophies ranging from Leber congenital amaurosis (LCA) to early-onset retinitispigmentosa (RP), due to developmental defects or loss of adhesion between photoreceptors and Müller glia cells, respectively. Whereas over 150 mutations have been found, no

Full Text Available Characterization of the electrical activity of the retina in the animal models of retinal degeneration has been carried out in part to understand the progression of retinal degenerative diseases like age-related macular degeneration (AMD and retinitispigmentosa (RP, but also to determine optimum stimulus paradigms for use with retinal prosthetic devices. The models most studied in this regard have been the two lines of mice deficient in the β-subunit of phosphodiesterase (rd1 and rd10 mice, where the degenerating retinas exhibit characteristic spontaneous hyperactivity and oscillatory local field potentials (LFPs. Additionally, there is a robust ~10 Hz rhythmic burst of retinal ganglion cell (RGC spikes on the trough of the oscillatory LFP. In rd1 mice, the rhythmic burst of RGC spikes is always phase-locked with the oscillatory LFP and this phase-locking property is preserved regardless of postnatal ages. However, in rd10 mice, the frequency of the oscillatory rhythm changes according to postnatal age, suggesting that this rhythm might be a marker of the stage of degeneration. Furthermore when a biphasic current stimulus is applied to rd10 mice degenerate retina, distinct RGC response patterns that correlate with the stage of degeneration emerge. This review also considers the significance of these response properties.

Full Text Available The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitispigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish and eyeless (cavefish morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2 hybrid progeny. We used next generation sequencing (RAD-seq and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax.

In human trials certain heat shock protein 90 (Hsp90) inhibitors, including 17-DMAG and NVP-AUY922, have caused visual disorders indicative of retinal dysfunction; others such as 17-AAG and ganetespib have not. To understand these safety profile differences we evaluated histopathological changes and exposure profiles of four Hsp90 inhibitors, with or without clinical reports of adverse ocular effects, using a rat retinalmodel. Retinal morphology, Hsp70 expression (a surrogate marker of Hsp90 inhibition), apoptotic induction and pharmacokinetic drug exposure analysis were examined in rats treated with the ansamycins 17-DMAG and 17-AAG, or with the second-generation compounds NVP-AUY922 and ganetespib. Both 17-DMAG and NVP-AUY922 induced strong yet restricted retinal Hsp70 up-regulation and promoted marked photoreceptor cell death 24 h after the final dose. In contrast, neither 17-AAG nor ganetespib elicited photoreceptor injury. When the relationship between drug distribution and photoreceptor degeneration was examined, 17-DMAG and NVP-AUY922 showed substantial retinal accumulation, with high retina/plasma (R/P) ratios and slow elimination rates, such that 51% of 17-DMAG and 65% of NVP-AUY922 present at 30 min post-injection were retained in the retina 6 h post-dose. For 17-AAG and ganetespib, retinal elimination was rapid (90% and 70% of drugs eliminated from the retina at 6 h, respectively) which correlated with lower R/P ratios. These findings indicate that prolonged inhibition of Hsp90 activity in the eye results in photoreceptor cell death. Moreover, the results suggest that the retina/plasma exposure ratio and retinal elimination rate profiles of Hsp90 inhibitors, irrespective of their chemical class, may predict for ocular toxicity potential. - Highlights: • In human trials some Hsp90 inhibitors cause visual disorders, others do not. • Prolonged inhibition of Hsp90 in the rat eye results in photoreceptor cell death. • Retina/plasma ratio and retinal

Stem cell therapy for retinal disease is under way, and several clinical trials are currently recruiting. These trials use human embryonic, foetal and umbilical cord tissue-derived stem cells and bone marrow-derived stem cells to treat visual disorders such as age-related macular degeneration, Stargardt's disease and retinitispigmentosa. Over a decade of analysing the developmental cues involved in retinal generation and stem cell biology, coupled with extensive surgical research, have yielded differing cellular approaches to tackle these retinopathies. Here, we review these various stem cell-based approaches for treating retinal diseases and discuss future directions and challenges for the field.

Irradiation by light in the far-red to near-infrared (NIR) region of the spectrum (photobiomodulation, PBM) has been demonstrated to attenuate the severity of neurodegenerative disease in experimental and clinical studies. The purpose of this study was to test the hypothesis that 670 nm PBM would protect against the loss of retinal function and improve photoreceptor survival in a rodent model of retinitispigmentosa, the P23H transgenic rat. P23H rat pups were treated once per day with a 670 nm LED array (180 sec treatments at 50 mW/cm2; fluence 9 joules/cm2) (Quantum Devices Inc., Barneveld WI) from postnatal day (p) 16-20 or from p10-20. Sham-treated rats were restrained, but not exposed to NIR light. The status of the retina was determined at p22 by assessment of mitochondrial function, oxidative stress and cell death. In a second series of studies, retinal status was assessed at p30 by measuring photoreceptor function by ERG and retinal morphology by Spectral Domain Optical Coherence Tomography (SD-OCT). 670 nm PBM increased retinal mitochondrial cytochrome oxidase activity and upregulated the retina's production of the key mitochondrial antioxidant enzyme, MnSOD. PBM also attenuated photoreceptor cell loss and improved photoreceptor function. PBM protects photoreceptors in the developing P23H retina, by augmenting mitochondrial function and stimulating antioxidant protective pathways. Photobiomodulation may have therapeutic potential, where mitochondrial damage is a step in the death of photoreceptors.

Clinical symptoms of diabetic retinopathy are not detectable until damage to the retina reaches an irreversible stage, at least by today's treatment standards. As a result, there is a push to develop new, "sub-clinical" methods of predicting the onset of diabetic retinopathy before the onset of irreversible damage. With diabetic retinopathy being associated with the accumulation of long-term mild damage to the retinal vasculature, retinal blood vessel permeability has been proposed as a key parameter for detecting preclinical stages of retinopathy. In this study, a kinetic modeling approach used to quantify vascular permeability in dynamic contrast-enhanced medical imaging was evaluated in noise simulations and then applied to retinal videoangiography data in a diabetic rat for the first time to determine the potential for this approach to be employed clinically as an early indicator of diabetic retinopathy. Experimental levels of noise were found to introduce errors of less than 15% in estimates of blood flow and extraction fraction (a marker of vascular permeability), and fitting of rat retinal fluorescein angiography data provided stable maps of both parameters.

Full Text Available A promising clinical application for stem and progenitor cell transplantation is in rescue therapy for degenerative diseases. This strategy seeks to preserve rather than restore host tissue function by taking advantage of unique properties often displayed by these versatile cells. In studies using different neurodegenerative disease models, transplanted human neural progenitor cells (hNPC protected dying host neurons within both the brain and spinal cord. Based on these reports, we explored the potential of hNPC transplantation to rescue visual function in an animal model of retinal degeneration, the Royal College of Surgeons rat.Animals received unilateral subretinal injections of hNPC or medium alone at an age preceding major photoreceptor loss. Principal outcomes were quantified using electroretinography, visual acuity measurements and luminance threshold recordings from the superior colliculus. At 90-100 days postnatal, a time point when untreated rats exhibit little or no retinal or visual function, hNPC-treated eyes retained substantial retinal electrical activity and visual field with near-normal visual acuity. Functional efficacy was further enhanced when hNPC were genetically engineered to secrete glial cell line-derived neurotrophic factor. Histological examination at 150 days postnatal showed hNPC had formed a nearly continuous pigmented layer between the neural retina and retinal pigment epithelium, as well as distributed within the inner retina. A concomitant preservation of host cone photoreceptors was also observed.Wild type and genetically modified human neural progenitor cells survive for prolonged periods, migrate extensively, secrete growth factors and rescue visual functions following subretinal transplantation in the Royal College of Surgeons rat. These results underscore the potential therapeutic utility of hNPC in the treatment of retinal degenerative diseases and suggest potential mechanisms underlying their effect in

Full Text Available The aim of this study was to investigate the effect of nerve growth factor (NGF administration on retinal ganglion cells (RGCs in experimentally induced glaucoma (GL and diabetic retinopathy (DR. GL was induced in adult rats by injection of hypertonic saline into the episcleral vein of the eye and diabetes (DT was induced by administration of streptozoticin. Control and experimental rats were treated daily with either ocular application of NGF or vehicle solution. We found that both animal models present a progressive degeneration of RGCs and changing NGF and VEGF levels in the retina and optic nerve. We then proved that NGF eye drop administration exerts a protective effect on these models of retinal degeneration. In brief, our findings indicate that NGF can play a protective role against RGC degeneration occurring in GL and DR and suggest that ocular NGF administration might be an effective pharmacological approach.

Full Text Available Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB, play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD, diabetes, glaucoma, retinal detachment, or retinitispigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.

Background: Retinitispigmentosa (RP) is the most common cause of inherited retinal degeneration and can occur in non-syndromic and syndromic forms. Syndromic RP is accompanied by other symptoms such as intellectual disability, hearing loss, or congenital abnormalities. Both forms are known to ex...

This article reports on the ability of observers who are sighted and those with low vision to make time-to-collision (TTC) estimations using video. The TTC estimations made by the observers with low vision were comparable to those made by the sighted observers, and both groups made underestimation errors that were similar to those that were…

The article describes a variation of Usher's Syndrome, a genetic condition characterized by visual and auditory impairments, in which moderate, postlingual, and sometimes progressive hearing impairments may go undetected. Identification guidelines are offered. (Author/CL)

of hereditary degenerative disorders of the retina, which are both genetically and clinically heterogeneous. The finding of ... causes of genetic blindness. The condition may be transmitted as an autosomal dominant, .... throughout the country conduct home visits in order to obtain blood specimens and collect pedigree data.

patients show early and severe impairment of pure rod responses (Pagon 1993). ... is characterized by total blindness or greatly impaired vision at birth or within ... gene, Mertk, in the Royal College of Surgeons (RCS) rat (D'Cruz et al 2000) ...

Full Text Available Abstract Background In this paper we present a novel scene retargeting technique to reduce the visual scene while maintaining the size of the key features. The algorithm is scalable to implementation onto portable devices, and thus, has potential for augmented reality systems to provide visual support for those with tunnel vision. We therefore test the efficacy of our algorithm on shrinking the visual scene into the remaining field of view for those patients. Methods Simple spatial compression of visual scenes makes objects appear further away. We have therefore developed an algorithm which removes low importance information, maintaining the size of the significant features. Previous approaches in this field have included seam carving, which removes low importance seams from the scene, and shrinkability which dynamically shrinks the scene according to a generated importance map. The former method causes significant artifacts and the latter is inefficient. In this work we have developed a new algorithm, combining the best aspects of both these two previous methods. In particular, our approach is to generate a shrinkability importance map using as seam based approach. We then use it to dynamically shrink the scene in similar fashion to the shrinkability method. Importantly, we have implemented it so that it can be used in real time without prior knowledge of future frames. Results We have evaluated and compared our algorithm to the seam carving and image shrinkability approaches from a content preservation perspective and a compression quality perspective. Also our technique has been evaluated and tested on a trial included 20 participants with simulated tunnel vision. Results show the robustness of our method at reducing scenes up to 50% with minimal distortion. We also demonstrate efficacy in its use for those with simulated tunnel vision of 22 degrees of field of view or less. Conclusions Our approach allows us to perform content aware video resizing in real time using only information from previous frames to avoid jitter. Also our method has a great benefit over the ordinary resizing method and even over other image retargeting methods. We show that the benefit derived from this algorithm is significant to patients with fields of view 20° or less.

Familial dysautonomia (FD) is an autosomal recessive congenital neuropathy that is caused by a mutation in the gene for inhibitor of kappa B kinase complex-associated protein ( IKBKAP ). Although FD patients suffer from multiple neuropathies, a major debilitation that affects their quality of life is progressive blindness. To determine the requirement for Ikbkap in the developing and adult retina, we generated Ikbkap conditional knockout (CKO) mice using a TUBA1a promoter-Cre ( Tα1-Cre ). In the retina, Tα1-Cre expression is detected predominantly in retinal ganglion cells (RGCs). At 6 months, significant loss of RGCs had occurred in the CKO retinas, with the greatest loss in the temporal retina, which is the same spatial phenotype observed in FD, Leber hereditary optic neuropathy, and dominant optic atrophy. Interestingly, the melanopsin-positive RGCs were resistant to degeneration. By 9 months, signs of photoreceptor degeneration were observed, which later progressed to panretinal degeneration, including RGC and photoreceptor loss, optic nerve thinning, Müller glial activation, and disruption of layers. Taking these results together, we conclude that although Ikbkap is not required for normal development of RGCs, its loss causes a slow, progressive RGC degeneration most severely in the temporal retina, which is later followed by indirect photoreceptor loss and complete retinal disorganization. This mouse model of FD is not only useful for identifying the mechanisms mediating retinal degeneration, but also provides a model system in which to attempt to test therapeutics that may mitigate the loss of vision in FD patients.

Ghrelin, a natural ligand for the growth hormone secretagogue receptor type 1a (GHSR-1a), may protect retinal neurons against glaucomatous injury. We therefore characterized the underlying mechanism of the ghrelin/GHSR-1a-mediated neuroprotection with a rat chronic intraocular hypertension (COH) model. The rat COH model was produced by blocking episcleral veins. A combination of immunohistochemistry, Western blot, TUNEL assay, and retrograde labeling of retinal ganglion cells (RGCs) was used. Elevation of intraocular pressure induced a significant increase in ghrelin and GHSR-1a expression in retinal cells, including RGCs and Müller cells. Western blot confirmed that the protein levels of ghrelin exhibited a transient upregulation at week 2 after surgery (G2w), while the GHSR-1a protein levels were maintained at high levels from G2w to G4w. In COH retinas, the ratio of LC3-II/LC-I and beclin1, two autophagy-related proteins, were increased from G1w to G4w, and the cleavage product of caspase3, an apoptotic executioner, was detected from G2w to G4w. Intraperitoneal injection of ghrelin significantly increased the number of surviving RGCs; inhibited the changes of LC3-II/LC-I, beclin1, and the cleavage products of caspase3; and reduced the number of TUNEL-positive cells in COH retinas. Ghrelin treatment also reversed the decreased levels of p-Akt and p-mTOR, upregulated GHSR-1a protein levels, and attenuated glial fibrillary acidic protein levels in COH retinas. All these results suggest that ghrelin may provide neuroprotective effect in COH retinas through activating ghrelin/GHSR-1a system, which was mediated by inhibiting retinal autophagy, ganglion cell apoptosis, and Müller cell gliosis.

Muscarinic acetylcholine receptor agonist pilocarpine reduces intraocular pressure (IOP) of glaucoma mainly by stimulating ciliary muscle contraction and then increasing aqueous outflow. It is of our great interest to know whether pilocarpine has the additional properties of retinal neuroprotection independent of IOP lowering in vitro and in vivo models. In rat primary retinal cultures, cell viability was measured using an MTT assay and the trypan blue exclusion method, respectively. Retinal ganglion cells (RGCs) were identified by immunofluorescence and quantified by flow cytometry. For the in vivo study, the retinal damage after retinal ischemia/reperfusion injury in rats was evaluated by histopathological study using hematoxylin and eosin staining, transmission electron microscopy, and immunohistochemical study on cleaved caspase-3, caspase-3, and ChAT. Pretreatment of pilocarpine attenuated glutamate-induced neurotoxicity of primary retinal neurons in a dose-dependent manner. Protection of pilocarpine in both retinal neurons and RGCs was largely abolished by the nonselective muscarinic receptor antagonist atropine and the M1-selective muscarinic receptor antagonist pirenzepine. After ischemia/reperfusion injury in retina, the inner retinal degeneration occurred including ganglion cell layer thinning and neuron lost, and the optic nerve underwent vacuolar changes. These degenerative changes were significantly lessened by topical application of 2% pilocarpine. In addition, the protective effect of pilocarpine on the ischemic rat retina was favorably reflected by downregulating the expression of activated apoptosis marker cleaved caspase-3 and caspase-3 and upregulating the expression of cholinergic cell marker ChAT. Taken together, this highlights pilocarpine through the activation of muscarinic receptors appear to afford significant protection against retinal neurons damage and optic nerve degeneration at clinically relevant concentrations. These data also

Platelet-derived growth factor (PDGF)-C is a member of the PDGF family and is critical for neuronal survival in the central nervous system. We studied the possible survival and antiapoptotic effects of PDGF-C on focal retinal lesions in Ccl2(-/-)/Cx3cr1(-/-) on C57BL/6N [Crb1(rd8)] (DKO rd8) background mice, a model for progressive and focal retinal degeneration. We found no difference in transcript and protein expression of PDGF-C in the retina between DKO rd8 mice and wild type (WT, C57BL/6N). Recombinant PDGF-CC protein (500 ng/eye) was injected intravitreally into the right eye of DKO rd8 mice with phosphate-buffered saline as controls into the left eye. The retinal effects of PDGF-C were assessed by fundoscopy, ocular histopathology, A2E levels, apoptotic molecule analysis, and direct flat mount retinal vascular labeling. We found that the PDGF-CC-treated eyes showed slower progression or attenuation of the focal retinal lesions, lesser photoreceptor and retinal pigment epithelial degeneration resulting in better-preserved photoreceptor structure. Lower expression of apoptotic molecules was detected in the PDGF-CC-treated eyes than in controls. In addition, no retinal neovascularization was observed after PDGF-CC treatment. Our results demonstrate that PDGF-C potently ameliorates photoreceptor degeneration via the suppression of apoptotic pathways without inducing retinal angiogenesis. The protective effects of PDGF-C suggest a novel alternative approach for potential age-related retinal degeneration treatment.

Pathological angiogenesis has been extensively explored by the mathematical modelling community over the past few decades, specifically in the contexts of tumour-induced vascularisation and wound healing. However, there have been relatively few attempts to model angiogenesis associated with normal development, despite the availability of animal models with experimentally accessible and highly ordered vascular topologies: for example, growth and development of the vascular plexus layers in the murine retina. The current study aims to address this issue through the development of a hybrid discrete-continuum mathematical model of the developing retinal vasculature in neonatal mice that is closely coupled with an ongoing experimental programme. The model of the functional vasculature is informed by a range of morphological and molecular data obtained over a period of several days, from 6 days prior to birth to approximately 8 days after birth. The spatio-temporal formation of the superficial retinal vascular plexus (RVP) in wild-type mice occurs in a well-defined sequence. Prior to birth, astrocytes migrate from the optic nerve over the surface of the inner retina in response to a chemotactic gradient of PDGF-A, formed at an earlier stage by migrating retinal ganglion cells (RGCs). Astrocytes express a variety of chemotactic and haptotactic proteins, including VEGF and fibronectin (respectively), which subsequently induce endothelial cell sprouting and modulate growth of the RVP. The developing RVP is not an inert structure; however, the vascular bed adapts and remodels in response to a wide variety of metabolic and biomolecular stimuli. The main focus of this investigation is to understand how these interacting cellular, molecular, and metabolic cues regulate RVP growth and formation. In an earlier one-dimensional continuum model of astrocyte and endothelial migration, we showed that the measured frontal velocities of the two cell types could be accurately reproduced

All know that retinitispigmentosa (RP) is a group of hereditary retinal degenerative diseases characterized by progressive dysfunction of photoreceptors and associated with progressive cells loss; nevertheless, little is known about how rods and cones loss affects the surviving inner retinal neurons and networks. Retinal ganglion cells (RGCs) process and convey visual information from retina to visual centers in the brain. The healthy various ion channels determine the normal reception and projection of visual signals from RGCs. Previous work on the Royal College of Surgeons (RCS) rat, as a kind of classical RP animal model, indicated that, at late stages of retinal degeneration in RCS rat, RGCs were also morphologically and functionally affected. Here, retrograde labeling for RGCs with Fluorogold was performed to investigate the distribution, density, and morphological changes of RGCs during retinal degeneration. Then, patch clamp recording, western blot, and immunofluorescence staining were performed to study the channels of sodium and potassium properties of RGCs, so as to explore the molecular and proteinic basis for understanding the alterations of RGCs membrane properties and firing functions. We found that the resting membrane potential, input resistance, and capacitance of RGCs changed significantly at the late stage of retinal degeneration. Action potential could not be evoked in a part of RGCs. Inward sodium current and outward potassium current recording showed that sodium current was impaired severely but only slightly in potassium current. Expressions of sodium channel protein were impaired dramatically at the late stage of retinal degeneration. The results suggested that the density of RGCs decreased, process ramification impaired, and sodium ion channel proteins destructed, which led to the impairment of electrophysiological functions of RGCs and eventually resulted in the loss of visual function.

The use of multipotent mesenchymal stem cells (MSCs) has been reported as promising for the treatment of numerous degenerative disorders including the eye. In retinal degenerative diseases, MSCs exhibit the potential to regenerate into retinal neurons and retinal pigmented epithelial cells in both in vitro and in vivo studies. Delivery of MSCs was found to improve retinal morphology and function and delay retinal degeneration. In this review, we revisit the therapeutic role of MSCs in the diseased eye. Furthermore, we reveal the possible cellular mechanisms and identify the associated signaling pathways of MSCs in reversing the pathological conditions of various ocular disorders such as age-related macular degeneration (AMD), retinitispigmentosa, diabetic retinopathy, and glaucoma. Current stem cell treatment can be dispensed as an independent cell treatment format or with the combination of other approaches. Hence, the improvement of the treatment strategy is largely subjected by our understanding of MSCs mechanism of action.

The ground state potential energy surface of the retinal chromophore of visual pigments (e.g., bovine rhodopsin) features a low-lying conical intersection surrounded by regions with variable charge-transfer and diradical electronic structures. This implies that dynamic electron correlation may have a large effect on the shape of the force fields driving its reactivity. To investigate this effect, we focus on mapping the potential energy for three paths located along the ground state CASSCF potential energy surface of the penta-2,4-dieniminium cation taken as a minimal model of the retinal chromophore. The first path spans the bond length alternation coordinate and intercepts a conical intersection point. The other two are minimum energy paths along two distinct but kinetically competitive thermal isomerization coordinates. We show that the effect of introducing the missing dynamic electron correlation variationally (with MRCISD) and perturbatively (with the CASPT2, NEVPT2, and XMCQDPT2 methods) leads, invariably, to a stabilization of the regions with charge transfer character and to a significant reshaping of the reference CASSCF potential energy surface and suggesting a change in the dominating isomerization mechanism. The possible impact of such a correction on the photoisomerization of the retinal chromophore is discussed.

Trypsin digest is the gold standard method to analyze the retinal vasculature (1-5). It allows visualization of the entire network of complex three-dimensional retinal blood vessels and capillaries by creating a two-dimensional flat-mount of the interconnected vascular channels after digestion of the non-vascular components of the retina. This allows one to study various pathologic vascular changes, such as microaneurysms, capillary degeneration, and abnormal endothelial to pericyte ratios. However, the method is technically challenging, especially in mice, which have become the most widely available animal model to study the retina because of the ease of genetic manipulations (6,7). In the mouse eye, it is particularly difficult to completely remove the non-vascular components while maintaining the overall architecture of the retinal blood vessels. To date, there is a dearth of literature that describes the trypsin digest technique in detail in the mouse. This manuscript provides a detailed step-by-step methodology of the trypsin digest in mouse retina, while also providing tips on troubleshooting difficult steps.

Full Text Available All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitispigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA, the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

Retinal degeneration (RD), such as age-related macular degeneration (AMD) and retinitispigmentosa, is one of the leading causes of blindness. Presently, no satisfactory therapeutic options are available for these diseases principally because the retina and retinal pigmented epithelium (RPE) do not regenerate, although wet AMD can be prevented from further progression by anti-vascular endothelial growth factor therapy. Nevertheless, stem/progenitor cell approaches exhibit enormous potential for RD treatment using strategies mainly aimed at the rescue and replacement of photoreceptors and RPE. The sources of stem/progenitor cells are classified into two broad categories in this review, which are (1) ocular-derived progenitor cells, such as retinal progenitor cells, and (2) non-ocular-derived stem cells, including embryonic stem cells, induced pluripotent stem cells, and mesenchymal stromal cells. Here, we discuss in detail the progress in the study of four predominant stem/progenitor cell types used in animal models of RD. A short overview of clinical trials involving the stem/progenitor cells is also presented. Currently, stem/progenitor cell therapies for RD still have some drawbacks such as inhibited proliferation and/or differentiation in vitro (with the exception of the RPE) and limited long-term survival and function of grafts in vivo. Despite these challenges, stem/progenitor cells represent the most promising strategy for RD treatment in the near future.

All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitispigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

·AIM: To evaluate the effect of different bevacizumab concentrations on retinal neovascularization in a retinopathy of prematurity(ROP) mouse model.·METHODS: A total of 60 of C57BL/6 J mice were exposed to 75% ±2% oxygen from postnatal d7 to postnatal d12. Fifteen nonexposed mice served as negative controls(group A). On d12, 30 mice(group C)were injected with 2.5 μg intravitreal bevacizumab(IVB),30 mice(group D) were injected with 1.25 μg IVB in one eye. The contralateral eyes were injected with balanced salt solution(BSS)(control group =group B). The adenosine diphosphatase(ADPase) histochemical technique was used for retinal flat mount to assess the oxygen-induced changes of retinal vessels.Neovascularization was quantified by counting the endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina. Histological changes were examined by light microscopy. The mRNA levels of vascular endothelial growth factor(VEGF) were quantified by Real-time PCR. Western-blotting analysis was performed to examine the expression of P-VEGFR.· RESULTS: Comparing with the control group B,regular distributions and reduced tortuosity of vessels were observed in our retinal flat mounts in groups C and D. The endothelial cell count per histological section was lower in groups C(P <0.0001) and D(P <0.0001) compared with the control group B. Histological evaluation showed no retinal toxicity in any group. In all oxygen treated groups VEGF mRNA expression was significantly increased as compared to age-matched controls. No significant change in VEGF mRNA expression could be achieved in either of the treatments or the oxygen controls. The results of the Western blot were consistent with that of the Real-time PCR analysis.·CONCLUSION: An intravitreal injection of bevacizumab is able to reduce angioproliferative retinopathy in a mouse model for oxygen-induced retinopathy.

The hyperosmolarity response of the standing potential was recorded in retinitispigmentosa (20 eyes), central (pericentral) retinitispigmentosa (4 eyes), pigmented paravenous retinochoroidal atrophy (2 eyes), fundus albipunctatus (8 eyes), and Stargardt's disease (or fundus flavimaculatus) (14 eyes). The light peak/dark trough ratio (the L/D ratio) and the Diamox response were also determined. The hyperosmolarity response was greatly suppressed (less than M-4SD; M and SD indicate respectively the mean and the standard deviation in normal control subjects) in all examined eyes with retinitispigmentosa (20 eyes) including retinitispigmentosa sine pigmento (8 eyes), central (pericentral) retinitispigmentosa (4 eyes), and pigmented paravenous retinochoroidal atrophy (2 eyes). The L/D ratio was larger than 1.26 (M-2.5 SD) in the half of the eyes with the above-described diseases. The hyperosmolarity response was abnormal (less than M-2 SD) in 4 of 8 eyes with fundus albipunctatus. The L/D ratio was normal in all 8 eyes. The hyperosmolarity response was abnormal (less than M-2 SD) in all 14 eyes with Stargardt's disease or fundus flavimaculatus. The L/D ratio was abnormal in 5 of these 14 eyes. The hyperosmolarity response was more frequently abnormal than the L/D ratio in the chorioretinal dystrophies mentioned above, and hence is useful particularly for early diagnosis of these disorders.

This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

To investigate the neuroprotective effects of scutellarin, an active component of the multifunctional traditional Chinese herb Erigeron breviscapus (vant.) Hand.-Mazz. (EBHM), which has been used as a neuroprotective therapy for cerebrovascular diseases. We performed the experiments using in vitro and in vivo models of retinal neurodegeneration. In the in vitro experiments, we exposed BV-2 cells to low oxygen levels in an incubator for 24 and 48 h to generate hypoxia models. We then treated these cells with scutellarin at concentrations of 2, 10, and 50 µM. Cell viability was measured using an enzyme-linked immunosorbent assay (ELISA). The levels of the components of the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome signaling pathway, including NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1, interleukin-18 (IL-18), and IL-1β were analyzed using western blots and ELISAs. In the in vivo study, we raised the intraocular pressure of Brown Norway rats to 60 mmHg for 30 min to generate a high intraocular pressure (HIOP) model, that is, an acute glaucoma model. The rats were then treated with scutellarin via oral gavage for 2 consecutive weeks. The relevant components of the NLRP3 inflammasome signaling pathway were analyzed with western blots and ELISAs. Retinal ganglion cells (RGCs) were retrogradely labeled using 4% Fluoro-Gold, and then the numbers of cells were calculated. Retinal microglial cells were labeled using immunofluorescence, and then the morphological changes were observed. In the in vitro cell viability experiments, 50 µM scutellarin statistically significantly enhanced the viability rate when compared to 2 µM and 10 µM scutellarin (hypoxia + 50 µM EBHM group: 94.01±2.130% and 86.02±2.520% after 24 and 48 h, respectively; hypoxia model group: 74.98±3.860% and 64.41±4.890% after 24 and 48 h, respectively; for all

Purpose To investigate the neuroprotective effects of scutellarin, an active component of the multifunctional traditional Chinese herb Erigeron breviscapus (vant.) Hand.-Mazz. (EBHM), which has been used as a neuroprotective therapy for cerebrovascular diseases. We performed the experiments using in vitro and in vivo models of retinal neurodegeneration. Methods In the in vitro experiments, we exposed BV-2 cells to low oxygen levels in an incubator for 24 and 48 h to generate hypoxia models. We then treated these cells with scutellarin at concentrations of 2, 10, and 50 µM. Cell viability was measured using an enzyme-linked immunosorbent assay (ELISA). The levels of the components of the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome signaling pathway, including NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1, interleukin-18 (IL-18), and IL-1β were analyzed using western blots and ELISAs. In the in vivo study, we raised the intraocular pressure of Brown Norway rats to 60 mmHg for 30 min to generate a high intraocular pressure (HIOP) model, that is, an acute glaucoma model. The rats were then treated with scutellarin via oral gavage for 2 consecutive weeks. The relevant components of the NLRP3 inflammasome signaling pathway were analyzed with western blots and ELISAs. Retinal ganglion cells (RGCs) were retrogradely labeled using 4% Fluoro-Gold, and then the numbers of cells were calculated. Retinal microglial cells were labeled using immunofluorescence, and then the morphological changes were observed. Results In the in vitro cell viability experiments, 50 µM scutellarin statistically significantly enhanced the viability rate when compared to 2 µM and 10 µM scutellarin (hypoxia + 50 µM EBHM group: 94.01±2.130% and 86.02±2.520% after 24 and 48 h, respectively; hypoxia model group: 74.98±3.860% and 64.41±4.890% after 24 and 48 h

Full Text Available Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA encapsulated in poly(D,L-lactic-co-glycolic acid (PLGA microspheres for the treatment of the retina in a rat model of retinitispigmentosa. PLGA microspheres (MSs containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 μm and the drug loading resulted 12.5 ± 0.8 μg TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSs-treated eyes as compared to those injected with unloaded PLGA particles. TUDCA-PLGA-MSs-treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitispigmentosa.

The aim of the present thesis was to develop, refine, and assess experimental models for the study of proliferative vitreo-retinal disorders. An intravitreal injection of a colloidal solution of microparticles was used in the primate eye to produce pathologic changes including intraocular cell invasion, cell proliferation, neovascularization, collagen synthesis, and tractional retinal detachment. In a separate primate model for laser-induced subretinal neovascularization, the origin and the occurrence of macrophages was evaluated. Examinations were performed using ophthalmoscopy, slit-lamp microscopy, light microscopy, and transmission electron microscopy. Cell cultures were employed to study the effects of vitreous humor and macrophages on the proliferation of cultured retinal pigment epithelial (RPE) cells and cultured fibroblasts using a Coulter counter. Morphologic changes were documented by phase micrography. A quantitative estimation of the extracellular matrix deposition of fibrous proteins by macrophage-modulated RPE cells as well as by vitreous-modulated RPE cells was done using enzymatic digestion and radioactive labeling techniques. A qualitative analysis of the types of collagen that was deposited in the extracellular matrices by vitreous modulated cultures was also made using indirect immunofluorescence. Using a newly developed RPE cell specific monoclonal antibody, the avidin-biotin-peroxidase labeling technique was finally employed to test the phenotypic epitope expression of macrophage-modulated and non-modulated RPE cells. A new experimental in vivo model for pathologic changes that characterize proliferative vitreo-retinal disorders was developed in the primate eye. In the model for laser-induced subretinal neovascularization, macrophages were shown to be principally recruited from the systemic circulation. Using cell cultures, it was found that both macrophage-conditioned medium and vitreous humor, separately or combined, exert mitogenic effects

Full Text Available Progressive retinal degenerations are the most common causes of complete blindness both in human and in dogs. Canine progressive retinal atrophy (PRA or degeneration resembles human retinitispigmentosa (RP and is characterized by a progressive loss of rod photoreceptor cells followed by a loss of cone function. The primary clinical signs are detected as vision impairment in a dim light. Although several genes have been associated with PRAs, there are still PRAs of unknown genetic cause in many breeds, including Papillons and Phalènes. We have performed a genome wide association and linkage studies in cohort of 6 affected Papillons and Phalènes and 14 healthy control dogs to map a novel PRA locus on canine chromosome 2, with a 1.9 Mb shared homozygous region in the affected dogs. Parallel exome sequencing of a trio identified an indel mutation, including a 1-bp deletion, followed by a 6-bp insertion in the CNGB1 gene. This mutation causes a frameshift and premature stop codon leading to probable nonsense mediated decay (NMD of the CNGB1 mRNA. The mutation segregated with the disease and was confirmed in a larger cohort of 145 Papillons and Phalènes (PFisher = 1.4×10(-8 with a carrier frequency of 17.2 %. This breed specific mutation was not present in 334 healthy dogs from 10 other breeds or 121 PRA affected dogs from 44 other breeds. CNGB1 is important for the photoreceptor cell function its defects have been previously associated with retinal degeneration in both human and mouse. Our study indicates that a frameshift mutation in CNGB1 is a cause of PRA in Papillons and Phalènes and establishes the breed as a large functional animal model for further characterization of retinal CNGB1 biology and possible retinal gene therapy trials. This study enables also the development of a genetic test for breeding purposes.

Full Text Available Abstract Background Development and maintenance of the blood-brain and blood-retinal barrier is critical for the homeostasis of brain and retinal tissue. Despite decades of research our knowledge of the formation and maintenance of the blood-brain (BBB and blood-retinal (BRB barrier is very limited. We have established an in vivo model to study the development and maintenance of these barriers by generating a transgenic zebrafish line that expresses a vitamin D-binding protein fused with enhanced green fluorescent protein (DBP-EGFP in blood plasma, as an endogenous tracer. Results The temporal establishment of the BBB and BRB was examined using this transgenic line and the results were compared with that obtained by injection of fluorescent dyes into the sinus venosus of embryos at various stages of development. We also examined the expression of claudin-5, a component of tight junctions during the first 4 days of development. We observed that the BBB of zebrafish starts to develop by 3 dpf, with expression of claudin-5 in the central arteries preceding it at 2 dpf. The hyaloid vasculature in the zebrafish retina develops a barrier function at 3 dpf, which endows the zebrafish with unique advantages for studying the BRB. Conclusion Zebrafish embryos develop BBB and BRB function simultaneously by 3 dpf, which is regulated by tight junction proteins. The Tg(l-fabp:DBP-EGFP zebrafish will have great advantages in studying development and maintenance of the blood-neural barrier, which is a new application for the widely used vertebrate model.

Usher syndrome is a deafness-blindness disorder. The blindness occurs from a progressive retinal degeneration that begins after deafness and after the retina has developed. Three clinical subtypes of Usher syndrome have been identified, with mutations in any one of six different genes giving rise to type 1, in any one of three different genes to type 2, and in one identified gene causing Usher type 3. Mutant mice for most of the genes have been studied; while they have clear inner ear defects, retinal phenotypes are relatively mild and have been difficult to characterize. The retinal functions of the Usher proteins are still largely unknown. Protein binding studies have suggested many interactions among the proteins, and a model of interaction among all the proteins in the photoreceptor synapse has been proposed. However this model is not supported by localization data from some laboratories, or the indication of any synaptic phenotype in mutant mice. An earlier suggestion, based on patient pathologies, of Usher protein function in the photoreceptor cilium continues to gain support from immunolocalization and mutant mouse studies, which are consistent with Usher protein interaction in the photoreceptor ciliary/periciliary region. So far, the most characterized Usher protein is myosin VIIa. It is present in the apical RPE and photoreceptor ciliary/periciliary region, where it is required for organelle transport and clearance of opsin from the connecting cilium, respectively. Usher syndrome is amenable to gene replacement therapy, but also has some specific challenges. Progress in this treatment approach has been achieved by correction of mutant phenotypes in Myo7a-null mouse retinas, following lentiviral delivery of MYO7A. PMID:17936325

Diabetic retinopathy (DR) is a major cause of blindness globally. Investigating the underlying mechanisms of DR would be aided by a suitable mouse model that developed key features seen in the human disease, and did so without carrying genetic modifications. This study was undertaken to produce such a model. Our panel of Collaborative Cross strains was screened for DR-like features after induction of diabetes by intravenous injection with alloxan or streptozotocin. Both flat-mounted whole-retina and histologic sections were studied for the presence of retinal lesions. Progression of DR was also studied by histologic examination of the retinal vascular and neural structure at various time points after diabetes onset. In addition, microarray investigations were conducted on retinas from control and diabetic mice. Features of DR such as degenerated pericytes, acellular capillaries, minor vascular proliferation, gliosis of Müller cells, and loss of ganglion cells were noted as early as day 7 in some mice. These lesions became more evident with time. After 21 days of diabetes, severe vascular proliferation, microaneurysms, preretinal damage, increased Müller cell gliosis, and damage to the outer retina were all obvious. Microarray studies found significant differential expression of multiple genes known to be involved in DR. The FOT_FB strain provides a useful model to investigate the pathogenesis of DR and to develop treatments for this vision-threatening disease.

Observations of RPE disruption and autofluorescence (AF) photobleaching at light levels below the ANSI photochemical maximum permissible exposure (MPE) (Morgan et al., 2008) indicates a demand to modify future light safety standards to protect the retina from harm. To establish safe light exposures, we measured the visible light action spectrum for RPE disruption in an in vivo monkey model with fluorescence adaptive optics retinal imaging. Using this high resolution imaging modality can provide insight into the consequences of light on a cellular level and allow for longitudinal monitoring of retinal changes. The threshold retinal radiant exposures (RRE) for RPE disruption were determined for 4 wavelengths (460, 488, 544, and 594 nm). The anaesthetized macaque retina was exposed to a uniform 0.5° × 0.5° field of view (FOV). Imaging within a 2° × 2° FOV was performed before, immediately after and at 2 week intervals for 10 weeks. At each wavelength, multiple RREs were tested with 4 repetitions each to determine the threshold for RPE disruption. For qualitative analysis, RPE disruption is defined as any detectable change from the pre exposure condition in the cell mosaic in the exposed region relative to the corresponding mosaic in the immediately surrounding area. We have tested several metrics to evaluate the RPE images obtained before and after exposure. The measured action spectrum for photochemical RPE disruption has a shallower slope than the current ANSI photochemical MPE for the same conditions and suggests that longer wavelength light is more hazardous than other measurements would suggest.

Full Text Available The central nervous system undergoing degeneration can be stabilized, and in some models can be restored to function, by neuroprotective treatments. Photobiomodulation (PBM and dietary saffron are distinctive as neuroprotectants in that they upregulate protective mechanisms, without causing measurable tissue damage. This study reports a first attempt to combine the actions of PBM and saffron. Our working hypothesis was that the actions of PBM and saffron in protecting retinal photoreceptors, in a rat light damage model, would be additive. Results confirmed the neuroprotective potential of each used separately, but gave no evidence that their effects are additive. Detailed analysis suggests that there is actually a negative interaction between PBM and saffron when given simultaneously, with a consequent reduction of the neuroprotection. Specific testing will be required to understand the mechanisms involved and to establish whether there is clinical potential in combining neuroprotectants, to improve the quality of life of people affected by retinal pathology, such as age-related macular degeneration, the major cause of blindness and visual impairment in older adults.

Fundus camera imaging of the retina is widely used to diagnose and manage ophthalmologic disorders including diabetic retinopathy, glaucoma, and age-related macular degeneration. Retinal images typically have a limited field of view, and multiple images can be joined together using an image registration technique to form a montage with a larger field of view. A variety of methods for retinal image registration have been proposed, but evaluating such methods objectively is difficult due to the lack of a reference standard for the true alignment of the individual images that make up the montage. A method of generating simulated retinal images by modeling the geometric distortions due to the eye geometry and the image acquisition process is described in this paper. We also present a validation process that can be used for any retinal image registration method by tracing through the distortion path and assessing the geometric misalignment in the coordinate system of the reference standard. The proposed method can be used to perform an accuracy evaluation over the whole image, so that distortion in the non-overlapping regions of the montage components can be easily assessed. We demonstrate the technique by generating test image sets with a variety of overlap conditions and compare the accuracy of several retinal image registration models. Copyright 2010 Elsevier B.V. All rights reserved.

Late-onset retinal macular degeneration (L-ORD) is an autosomal dominant inherited disorder caused by a single missense mutation (S163R) in the CTRP5/C1QTNF5 protein. Early phenotypic features of L-ORD include: dark adaptation abnormalities, nyctalopia, and drusen deposits in the peripheral macular region. Apart from posterior segment abnormalities, these patients also develop abnormally long anterior lens zonules. In the sixth decade of life the rod and cone function declines, accompanied by electroretinogram (ERG) abnormalities. Some patients also develop choroidal neovascularization and glaucoma. In order to understand the disease pathology and mechanisms involved in retinal dystrophy, we generated a knock-in (Ctrp5(+/-)) mouse model carrying the disease-associated mutation in the mouse Ctrp5/C1QTNF5 gene. These mice develop slower rod-b wave recovery consistent with early dark adaptation abnormalities, accumulation of hyperautofluorescence spots, retinal pigment epithelium abnormalities, drusen, Bruch's membrane abnormalities, loss of photoreceptors, and retinal vascular leakage. The Ctrp5(+/-) mice, which have most of the pathological features of age-related macular degeneration, are unique and may serve as a valuable model both to understand the molecular pathology of late-onset retinal degeneration and to evaluate therapies.

Full Text Available Abstract Background Several forms of progressive retinal atrophy (PRA segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG. Results Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests. Conclusion Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3 and propose it as a potential model for the homologous human disease, X-Linked RetinitisPigmentosa.

Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG). Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests. Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3) and propose it as a potential model for the homologous human disease, X-Linked RetinitisPigmentosa.

The purpose of this study was to establish, and characterize a porcine model of acute, controlled retinal ischemia. The controlled retinal ischemia was produced by clamping the ocular perfusion pressure (OPP) in the left eye to 5 mm Hg for 2 h. The OPP was defined as mean arterial blood pressure...... of the amplitudes obtained in the experimental, left eye, and the control, right eye. Quantitative histology was performed to measure the survival of ganglion cells, amacrine cells and horizontal cells 2-6 weeks after the ischemic insult. An OPP of 5 mm Hg for 2h induced significant reductions in the amplitudes...... the ischemic insult. This model seems to be suitable for investigations of therapeutic initiatives in diseases involving acute retinal ischemia....

Preclinical studies of vascular retinal diseases rely on the assessment of developmental dystrophies in the oxygen induced retinopathy rodent model. The quantification of vessel tufts and avascular regions is typically computed manually from flat mounted retinas imaged using fluorescent probes that highlight the vascular network. Such manual measurements are time-consuming and hampered by user variability and bias, thus a rapid and objective method is needed. Here, we introduce a machine learning approach to segment and characterize vascular tufts, delineate the whole vasculature network, and identify and analyze avascular regions. Our quantitative retinal vascular assessment (QuRVA) technique uses a simple machine learning method and morphological analysis to provide reliable computations of vascular density and pathological vascular tuft regions, devoid of user intervention within seconds. We demonstrate the high degree of error and variability of manual segmentations, and designed, coded, and implemented a set of algorithms to perform this task in a fully automated manner. We benchmark and validate the results of our analysis pipeline using the consensus of several manually curated segmentations using commonly used computer tools. The source code of our implementation is released under version 3 of the GNU General Public License ( https://www.mathworks.com/matlabcentral/fileexchange/65699-javimazzaf-qurva ).

The structure of the retina suggests that it should be treated (at least from the computational point of view), as a layered computer. Different retinal cells contribute to the coding of the signals down to ganglion cells. Also, because of the nature of the specialization of some ganglion cells, the structure suggests that all these specialization processes should take place at the inner plexiform layer and they should be of a local character, prior to a global integration and frequency-spike coding by the ganglion cells. The framework we propose consists of a layered computational structure, where outer layers provide essentially with band-pass space-time filtered signals which are progressively delayed, at least for their formal treatment. Specialization is supposed to take place at the inner plexiform layer by the action of spatio-temporal microkernels (acting very locally), and having a centerperiphery space-time structure. The resulting signals are then integrated by the ganglion cells through macrokernels structures. Practically all types of specialization found in different vertebrate retinas, as well as the quasilinear behavior in some higher vertebrates, can be modeled and simulated within this framework. Finally, possible feedback from central structures is considered. Though their relevance to retinal processing is not definitive, it is included here for the sake of completeness, since it is a formal requisite for recursiveness.

Hallmarks of RetinitisPigmentosa (RP), a family of genetic diseases, are a typical rod-cone-degeneration with initial night blindness and loss of peripheral vision, followed by decreased daylight sight and progressive visual acuity loss up to legal blindness. Great heterogeneity in nature and function of mutated genes, variety of mutations for each of them, variability in phenotypic appearance and transmission modality contribute to make RP a still incurable disease. Translational research relies on appropriate animal models mimicking the genetic and phenotypic diversity of the human pathology. Here, we provide a systematic, morphological and functional analysis of Rho Tvrm4 /Rho + rhodopsin mutant mice, originally described in 2010 and portraying several features of common forms of autosomal dominant RP caused by gain-of-function mutations. These mice undergo photoreceptor degeneration only when exposed briefly to strong, white light and allow controlled timing of induction of rod and cone death, which therefore can be elicited in adult animals, as observed in human RP. The option to control severity and retinal extent of the phenotype by regulating intensity and duration of the inducing light opens possibilities to exploit this model for multiple experimental purposes. Altogether, the unique features of this mutant make it an excellent resource for retinal degeneration research.

The Royal College of Surgeons (RCS) rat is a widely studied animal model of retinal degeneration in which the inability of the retinal pigment epithelium (RPE) to phagocytize shed photoreceptor outer segments leads to a progressive loss of rod and cone photoreceptors. We recently used positional cloning to demonstrate that the gene Mertk likely corresponds to the retinal dystrophy (rdy) locus of the RCS rat. In the present study, we sought to determine whether gene transfer of Mertk to a RCS rat retina would result in correction of the RPE phagocytosis defect and preservation of photoreceptors. We used subretinal injection of a recombinant replication-deficient adenovirus encoding rat Mertk to deliver the gene to the eyes of young RCS rats. Electrophysiological assessment of animals 30 days after injection revealed an increased sensitivity of treated eyes to low-intensity light. Histologic and ultrastructural assessment demonstrated substantial sparing of photoreceptors, preservation of outer segment structure, and correction of the RPE phagocytosis defect in areas surrounding the injection site. Our results provide definitive evidence that mutation of Mertk underlies the RCS retinal dystrophy phenotype, and that the phenotype can be corrected by treatment of juvenile animals. To our knowledge, this is the first demonstration of complementation of both a functional cellular defect (phagocytosis) and a photoreceptor degeneration by gene transfer to the RPE. These results, together with the recent discovery of MERTK mutations in individuals with retinitispigmentosa, emphasize the importance of the RCS rat as a model for gene therapy of diseases that arise from RPE dysfunction.

Activation of neurons at different depths within the retina and at various eccentricities from the stimulating electrode will presumably influence the visual percepts created by a retinal prosthesis. With an electrical prosthesis, neurons will be activated in relation to the stimulating charge that impacts their cell membranes. The common model used to predict charge density is Coulomb's law, also known as the square law. We propose a modified model that can be used to predict neuronal depth that takes into account: (1) finite dimensions related to the position and size of the stimulating and return electrodes and (2) two-dimensional displacements of neurons with respect to the electrodes, two factors that are not considered in the square law model. We tested our model by using in vitro physiological threshold data that we had obtained previously for eight OFF-center brisk-transient rabbit retinal ganglion cells. For our most spatially dense threshold data (25 µm increments up to 100 µm from the cell body), our model estimated the depth of one RGC to be 76 ± 76 µm versus 87 ± 62 µm (median: SD) for the square law model, respectively. This difference was not statistically significant. For the seven other RGCs for which we had obtained threshold data up to 800 µm from the cell body, the estimate of the RGC depth (using data obtained along the X axis) was 96 ± 74 versus 20 ± 20 µm for the square law and our modified model, respectively. Although this difference was not statistically significant (Student t-test: p = 0.12), our model provided median values much closer to the estimated depth of these RGCs (Gt25 µm). This more realistic estimate of cell depth predicted by our model is not unexpected in this latter data set because of the more spatially distributed threshold data points that were evaluated. Our model has theoretical advantages over the traditional square law model under certain conditions, especially when considering neurons that are

Full Text Available Fan Yang, Dongmei Wang, Lingling Wu, Ying Li Ophthalmology Department, Peking University Third Hospital, Beijing, People’s Republic of China Purpose: To study the effects of triptolide, a Chinese herb extract, on retinal ganglion cells (RGCs in a rat model of chronic glaucoma.Methods: Eighty Wistar rats were randomly divided into triptolide group (n=40 and normal saline (NS group (n=40. Angle photocoagulation was used to establish the model of glaucoma, with right eye as laser treated eye and left eye as control eye. Triptolide group received triptolide intraperitoneally daily, while NS group received NS. Intraocular pressure (IOP, anti-CD11b immunofluorescent stain in retina and optic nerve, RGCs count with Nissel stain and microglia count with anti-CD11b immunofluorescence stain in retina flat mounts, retinal tumor necrosis factor (TNF-α mRNA detection by reverse transcription–polymerase chain reaction, and double immunofluorescent labeling with anti-TNF-α and anti-CD11b in retinal frozen section were performed.Results: Mean IOP of the laser treated eyes significantly increased 3 weeks after photocoagulation (P<0.05, with no statistical difference between the two groups (P>0.05. RGCs survival in the laser treated eyes was significantly improved in the triptolide group than the NS group (P<0.05. Microglia count in superficial retina of the laser treated eyes was significantly less in the triptolide group (30.40±4.90 than the NS group (35.06±7.59 (P<0.05. TNF-α mRNA expression in the retina of the laser treated eyes in the triptolide group decreased by 60% compared with that in the NS group (P<0.01. The double immunofluorescent labeling showed that TNF-α was mainly distributed around the microglia.Conclusion: Triptolide improved RGCs survival in this rat model of chronic glaucoma, which did not depend on IOP decrease but might be exerted by inhibiting microglia activities and reducing TNF-α secretion. Keywords: glaucoma, triptolide

Despite all the advancements in modern ophthalmology, disease can affect vision, resulting in blindness. Worldwide, there are 200 000 people who have retinitispigmentosa, 2 million with age-related macular degeneration (AMD) and 6 million have other forms of sight loss.

The GNAT1 gene encodes the α subunit of the rod transducin protein, a key element in the rod phototransduction cascade. Variants in GNAT1 have been implicated in stationary night-blindness in the past, but unlike other proteins in the same pathway, it has not previously been implicated in retinitispigmentosa.

Full Text Available BACKGROUND: To characterize the sequential events that are taking place in retinal neurodegeneration in a murine model of spontaneous type 2 diabetes (db/db mouse. METHODS: C57BLKsJ-db/db mice were used as spontaneous type 2 diabetic animal model, and C57BLKsJ-db/+ mice served as the control group. To assess the chronological sequence of the abnormalities the analysis was performed at different ages (8, 16 and 24 weeks. The retinas were evaluated in terms of morphological and functional abnormalities [electroretinography (ERG]. Histological markers of neurodegeneration (glial activation and apoptosis were evaluated by immunohistochemistry. In addition glutamate levels and glutamate/aspartate transporter (GLAST expression were assessed. Furthermore, to define gene expression changes associated with early diabetic retinopathy a transcriptome analyses was performed at 8 week. Furthermore, an additional interventional study to lower blood glucose levels was performed. RESULTS: Glial activation was higher in diabetic than in non diabetic mice in all the stages (p<0.01. In addition, a progressive loss of ganglion cells and a significant reduction of neuroretinal thickness were also observed in diabetic mice. All these histological hallmarks of neurodegeneration were less pronounced at week 8 than at week 16 and 24. Significant ERG abnormalities were present in diabetic mice at weeks 16 and 24 but not at week 8. Moreover, we observed a progressive accumulation of glutamate in diabetic mice associated with an early downregulation of GLAST. Morphological and ERG abnormalities were abrogated by lowering blood glucose levels. Finally, a dysregulation of several genes related to neurotransmission and oxidative stress such as UCP2 were found at week 8. CONCLUSIONS: Our results suggest that db/db mouse reproduce the features of the neurodegenerative process that occurs in the human diabetic eye. Therefore, it seems an appropriate model for investigating the

Full Text Available Background/Aims: Retinitispigmentosa (RP is characterized by degeneration of photoreceptors, and there are currently no effective treatments for this disease. However, curcumin has shown neuroprotectant efficacy in a RP rat and swine model, and thus, may have neuroprotective effects in this disease. Methods: Immunofluorescence staining, electroretinogram recordings, and behavioral tests were used to analyze the effects of curcumin and the underlying mechanism in retinal degeneration 1 (rd1 mice. Results: The number of apoptotic cells in the retina of rd1 mice at postnatal day 14 significantly decreased with curcumin treatment and visual function was improved. The activation of microglia and secretion of chemokines and matrix metalloproteinases in the retina were inhibited by curcumin. These effects were also observed in a co-culture of BV2 microglial cells and retina-derived 661W cells. Conclusions: Curcumin delayed retinal degeneration by suppressing microglia activation in the retina of rd1 mice. Thus, it may be an effective treatment for neurodegenerative disorders such as RP.

Full Text Available Progressive retinal atrophy is a common cause of blindness in the dog and affects >100 breeds. It is characterized by gradual vision loss that occurs due to the degeneration of photoreceptor cells in the retina. Similar to the human counterpart retinitispigmentosa, the canine disorder is clinically and genetically heterogeneous and the underlying cause remains unknown for many cases. We use a positional candidate gene approach to identify putative variants in the Hungarian Puli breed using genotyping data of 14 family-based samples (CanineHD BeadChip array, Illumina and whole-genome sequencing data of two proband and two parental samples (Illumina HiSeq 2000. A single nonsense SNP in exon 2 of BBS4 (c.58A > T, p.Lys20* was identified following filtering of high quality variants. This allele is highly associated (PCHISQ = 3.425e−14, n = 103 and segregates perfectly with progressive retinal atrophy in the Hungarian Puli. In humans, BBS4 is known to cause Bardet–Biedl syndrome which includes a retinitispigmentosa phenotype. From the observed coding change we expect that no functional BBS4 can be produced in the affected dogs. We identified canine phenotypes comparable with Bbs4-null mice including obesity and spermatozoa flagella defects. Knockout mice fail to form spermatozoa flagella. In the affected Hungarian Puli spermatozoa flagella are present, however a large proportion of sperm are morphologically abnormal and <5% are motile. This suggests that BBS4 contributes to flagella motility but not formation in the dog. Our results suggest a promising opportunity for studying Bardet–Biedl syndrome in a large animal model.

Purpose of review Ophthalmologists and rheumatologists frequently miscommunicate in consulting on patients with retinal vasculitis. This report seeks to establish a common understanding of the term, retinal vasculitis, and to review recent papers on this diagnosis. Recent findings 1) The genetic basis of some rare forms of retinal vascular disease have recently been described. Identified genes include CAPN5, TREX1, and TNFAIP3; 2) Behçet’s disease is a systemic illness that is very commonly associated with occlusive retinal vasculitis; 3) retinal imaging including fluorescein angiography and other newer imaging modalities has proven crucial to the identification and characterization of retinal vasculitis and its complications; 4) although monoclonal antibodies to IL-17A or IL-1 beta failed in trials for Behçet’s disease, antibodies to TNF alpha, either infliximab or adalimumab, have demonstrated consistent benefit in managing this disease. Interferon treatment and B cell depletion therapy via rituximab may be beneficial in certain types of retinal vasculitis. Summary Retinal vasculitis is an important entity for rheumatologists to understand. Retinal vasculitis associated with Behçet’s disease responds to monoclonal antibodies that neutralize TNF, but the many other forms of non-infectious retinal vasculitis may require alternate therapeutic management. PMID:26945335

Full Text Available Vision loss in glaucoma is caused by progressive dysfunction of retinal ganglion cells (RGCs and optic nerve atrophy. Here, we investigated the effectiveness of BDNF treatment to preserve vision in a glaucoma experimental model. As an established experimental model, we used the DBA/2J mouse, which develops chronic intraocular pressure (IOP elevation that mimics primary open-angle glaucoma (POAG. IOP was measured at different ages in DBA/2J mice. Visual function was monitored using the steady-state Pattern Electroretinogram (P-ERG and visual cortical evoked potentials (VEP. RGC alterations were assessed using Brn3 immunolabeling, and confocal microscope analysis. Human recombinant BDNF was dissolved in physiological solution (0.9% NaCl; the effects of repeated intravitreal injections and topical eye BDNF applications were independently evaluated in DBA/2J mice with ocular hypertension. BDNF level was measured in retinal homogenate by ELISA and western blot. We found a progressive decline of P-ERG and VEP responses in DBA/2J mice between 4 and 7 months of age, in relationship with the development of ocular hypertension and the reduction of Brn3 immunopositive RGCs. Conversely, repeated intravitreal injections (BDNF concentration = 2 µg/µl, volume = 1 µl, for each injection; 1 injection every four days, three injections over two weeks and topical eye application of BDNF eye-drops (12 µg/µl, 5 µl eye-drop every 48 h for two weeks were able to rescue visual responses in 7 month DBA/2J mice. In particular, BDNF topical eye treatment recovered P-ERG and VEP impairment increasing the number of Brn3 immunopositive RGCs. We showed that BDNF effects were independent of IOP reduction. Thus, topical eye treatment with BDNF represents a promisingly safe and feasible strategy to preserve visual function and diminish RGC vulnerability to ocular hypertension.

To evaluate if coenzyme Q10 (CoQ10) can protect retinal ganglion cells (RGCs) from apoptosis and, when instilled as eye drops on the cornea, if it can reach the retina and exert its antiapoptotic activity in this area in a mouse model of kainate (KA)-induced retinal damage. Rat primary or cultured RGCs were subjected to glutamate (50 μM) or chemical hypoxia (Antimycin A, 200 μM) or serum withdrawal (FBS, 0.5%) in the presence or absence of CoQ10 (10 μM). Cell viability was evaluated by light microscopy and fluorescence-activated cell sorting analyses. Apoptosis was evaluated by caspase 3/7 activity and mitochondrion depolarization tetramethylrhodamine ethyl ester analysis. CoQ10 transfer to the retina following its instillation as eye drops on the cornea was quantified by HPLC. Retinal protection by CoQ10 (10 μM) eye drops instilled on the cornea was then evaluated in a mouse model of KA-induced excitotoxic retinal cell apoptosis by cleaved caspase 3 immunohistofluorescence, caspase 3/7 activity assays, and quantification of inhibition of RGC loss. CoQ10 significantly increased viable cells by preventing RGC apoptosis. Furthermore, when topically applied as eye drops to the cornea, it reached the retina, thus substantially increasing local CoQ10 concentration and protecting retinal layers from apoptosis. The ability of CoQ10 eye drops to protect retinal cells from apoptosis in the mouse model of KA-induced retinal damage suggests that topical CoQ10 may be evaluated in designing therapies for treating apoptosis-driven retinopathies.

Full Text Available Glaucoma is an optic neuropathy, commonly associated with elevated intraocular pressure (IOP characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells which could lead to loss of vision. Endothelin-1 (ET-1 is a 21-amino acid vasoactive peptide that plays a key role in the pathogenesis of glaucoma; however, the receptors mediating these effects have not been defined. In the current study, endothelin B (ET(B receptor expression was assessed in vivo, in the Morrison's ocular hypertension model of glaucoma in rats. Elevation of IOP in Brown Norway rats produced increased expression of ET(B receptors in the retina, mainly in retinal ganglion cells (RGCs, nerve fiber layer (NFL, and also in the inner plexiform layer (IPL and inner nuclear layer (INL. To determine the role of ET(B receptors in neurodegeneration, Wistar-Kyoto wild type (WT and ET(B receptor-deficient (KO rats were subjected to retrograde labeling with Fluoro-Gold (FG, following which IOP was elevated in one eye while the contralateral eye served as control. IOP elevation for 4 weeks in WT rats caused an appreciable loss of RGCs, which was significantly attenuated in KO rats. In addition, degenerative changes in the optic nerve were greatly reduced in KO rats compared to those in WT rats. Taken together, elevated intraocular pressure mediated increase in ET(B receptor expression and its activation may contribute to a decrease in RGC survival as seen in glaucoma. These findings raise the possibility of using endothelin receptor antagonists as neuroprotective agents for the treatment of glaucoma.

AIM: To investigate the expression and role of nuclear factor κB(NF-κB) in diabetic retinopathy(DR) and its relationship with neovascularization and retinal cell apoptosis. METHODS: A total of 80 male Wistar rats were randomly assigned to control(4, 8, 12 and 16 wk, n =10 in each group) and diabetes mellitus(DM) groups(4, 8, 12 and 16wk, n =10 in each group). A diabetic rat model was established by intraperitoneal injection of streptozotocin(60 mg/kg). After 4, 8, 12 and 16 wk, rats were sacrificed.Retinal layers and retinal neovascularization growth were stained with hematoxylin-eosin and examined under light microscopy. Cell apoptosis in the retina was detected by Td T-mediated d UTP nick end labeling, and NF-κB distribution and expression in the retina was determined using immunohistochemistry. RESULTS: DM model success rate up to 100%.Diabetes model at each time point after the experimental groupcompared with the control group, the blood glucose was significantly increased, decreased body weight, each time point showed significant differences compared with the control group(P <0.01). After 12 wk other pathological changes in the retina of diabetic rats were observed; after 16 wk, neovascularization were observed. After 1mo, retinal cell apoptosis was observed.Compared with the control group, NF-κB expression in the DM group significantly increased with disease duration.CONCLUSION: With the prolonging of DM progression,the expression NF-κB increases. NF-κB may be related to retinal cell apoptosis and neovascularization.

Retinal vasculitis is a sight-threatening intraocular inflammation affecting the retinal vessels. It may occur as an isolated ocular condition, as a manifestation of infectious or neoplastic disorders, or in association with a systemic inflammatory disease. The search for an underlying etiology should be approached in a multidisciplinary fashion based on a thorough history, review of systems, physical examination, and laboratory evaluation. Discrimination between infectious and noninfectious etiologies of retinal vasculitis is important because their treatment is different. This review is based on recently published articles on retinal vasculitis and deals with its clinical diagnosis, its link with systemic diseases, and its laboratory investigation.

Full Text Available Prurigo pigmentosa is a rare inflammatory dermatosis that primarily affects adolescents and young adults. Even though it is most commonly seen in Japanese women, other countries have reported cases with increasing frequency. It is characterized by erythematous papules and macules on the trunk, neck and chest that resolve leaving a reticulate hyperpigmentation. Some endogenous factors related with ketosis like fasting, diet, diabetes, pregnancy and exogenous agents like chrome, nickel, para-amino compounds have been accused of playing a role in etiology. Here we would like to present a case of a 16-year-old female patient who was referred to our clinic with pruritic lesions on the trunk and neck, consistent with the initial phase of prurigo pigmentosa, after a period of strict diet. Prurigo pigmentosa is a disease with distinctive histologic and clinical features. Due to its rare occurrence, an accurate diagnosis may be particularly challenging. Clinicopathological correlation is therefore crucial in the diagnosis of the disease in its early phase.

The early stages of ocular diseases such as Diabetic Retinopathy are manifested by morphological changes in retinal tissue occurring on cellular level. Therefore, a number of ophthalmic diseases can be diagnosed at an early stage by detecting spatial and temporal variations in the scattering profile of retinal tissue. It was recently demonstrated that, OCT can be used to probe the functional response of retinal photoreceptors to external light stimulation [1]-[3]. fUHROCT measures localized differential changes in the retina reflectivity over time resulting from external light stimulation of the retina. Currently the origins of the observed reflectivity changes are not well understood. However, due to the complex nature of retinal physiology using purely experimental approaches in this case is problematic. For example fUHROCT is sensitive to small changes in the refractive index of biological tissue which as demonstrated previously, can result from a number of processes such as membrane hyperpolarization, osmotic swelling, metabolic changes, etc. In this paper, we present a computational model of interaction between photoreceptor cells and optical plane wave based on the Finite Integration Technique (FIT).

Purpose. To establish the zebrafish platinum mutant as a model for studying vision defects caused by syndromic albinism diseases such as Chediak-Higashi syndrome, Griscelli syndrome, and Hermansky-Pudlak syndrome (HPS). Methods. Bulked segregant analysis and candidate gene sequencing revealed that the zebrafish platinum mutation is a single-nucleotide insertion in the vps11 (vacuolar protein sorting 11) gene. Expression of vps11 was determined by RT-PCR and in situ hybridization. Mutants were analyzed for pigmentation defects and retinal disease by histology, immunohistochemistry, and transmission electron microscopy. Results. Phenocopy and rescue experiments determined that a loss of Vps11 results in the platinum phenotype. Expression of vps11 appeared ubiquitous during zebrafish development, with stronger expression in the developing retina and retinal pigmented epithelium (RPE). Zebrafish platinum mutants exhibited reduced pigmentation in the body and RPE; however, melanophore development, migration, and dispersion occurred normally. RPE, photoreceptors, and inner retinal neurons formed normally in zebrafish platinum mutants. However, a gradual loss of RPE, an absence of mature melanosomes, and the subsequent degradation of RPE/photoreceptor interdigitation was observed. Conclusions. These data show that Vps11 is not necessary for normal retinal development or initiation of melanin biosynthesis, but is essential for melanosome maturation and healthy maintenance of the RPE and photoreceptors. PMID:21330665

Full Text Available Progression of age-related macular degeneration has been linked to iron dysregulation and oxidative stress that induce apoptosis of neural retinal cells. Since both antioxidants and chelating agents have been reported to reduce the progression of retinal lesions associated with AMD in experimental animals, the present study evaluates the ability of multi-functional antioxidants containing functional groups that can independently chelate redox metals and quench free radicals to protect the retina against light-induced retinal degeneration, a rat model of dry atrophic AMD.Proof of concept studies were conducted to evaluate the ability of 4-(5-hydroxypyrimidin-2-yl-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4 and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8 to reduce retinal damage in 2-week dark adapted Wistar rats exposed to 1000 lx of light for 3 hours. Assessment of the oxidative stress markers 4- hydroxynonenal and nitrotyrosine modified proteins and Thioredoxin by ELISA and Western blots indicated that these compounds reduced the oxidative insult caused by light exposure. The beneficial antioxidant effects of these compounds in providing significant functional and structural protection were confirmed by electroretinography and quantitative histology of the retina.The present study suggests that multi-functional compounds may be effective candidates for preventive therapy of AMD.

Full Text Available Leber congenital amaurosis (LCA is a genetically heterogeneous group of retinal diseases that cause congenital blindness in infants and children. Mutations in the GUCY2D gene that encodes retinal guanylate cyclase-1 (retGC1 were the first to be linked to this disease group (LCA type 1 [LCA1] and account for 10%-20% of LCA cases. These mutations disrupt synthesis of cGMP in photoreceptor cells, a key second messenger required for function of these cells. The GUCY1*B chicken, which carries a null mutation in the retGC1 gene, is blind at hatching and serves as an animal model for the study of LCA1 pathology and potential treatments in humans.A lentivirus-based gene transfer vector carrying the GUCY2D gene was developed and injected into early-stage GUCY1*B embryos to determine if photoreceptor function and sight could be restored to these animals. Like human LCA1, the avian disease shows early-onset blindness, but there is a window of opportunity for intervention. In both diseases there is a period of photoreceptor cell dysfunction that precedes retinal degeneration. Of seven treated animals, six exhibited sight as evidenced by robust optokinetic and volitional visual behaviors. Electroretinographic responses, absent in untreated animals, were partially restored in treated animals. Morphological analyses indicated there was slowing of the retinal degeneration.Blindness associated with loss of function of retGC1 in the GUCY1*B avian model of LCA1 can be reversed using viral vector-mediated gene transfer. Furthermore, this reversal can be achieved by restoring function to a relatively low percentage of retinal photoreceptors. These results represent a first step toward development of gene therapies for one of the more common forms of childhood blindness.

Full Text Available Primary open angle glaucoma (POAG is a neurodegenerative disease characterized by physiological intraocular hypertension that causes damage to the retinal ganglion cells (RGCs. In the past, RGC damage in POAG was suggested to have been attributed to RGC apoptosis. However, in the present study, we applied a model closer to human POAG through the use of a chronic hypertensive glaucoma model in rhesus monkeys to investigate whether another mode of progressive cell death, autophagy, was activated in the glaucomatous retinas. First, in the glaucomatous retinas, the levels of LC3B-II, LC3B-II/LC3B-I and Beclin 1 increased as demonstrated by Western blot analyses, whereas early or initial autophagic vacuoles (AVi and late or degraded autophagic vacuoles (AVd accumulated in the ganglion cell layer (GCL and in the inner plexiform layer (IPL as determined by transmission electron microscopy (TEM analysis. Second, lysosome activity and autophagosome-lysosomal fusion increased in the RGCs of the glaucomatous retinas, as demonstrated by Western blotting against lysosome associated membrane protein-1 (LAMP1 and double labeling against LC3B and LAMP1. Third, apoptosis was activated in the glaucomatous eyes with increased levels of caspase-3 and cleaved caspase-3 and an increased number of TUNEL-positive RGCs. Our results suggested that autophagy was activated in RGCs in the chronic hypertensive glaucoma model of rhesus monkeys and that autophagy may have potential as a new target for intervention in glaucoma treatment.

Retinal pigmented epithelium (RPE), the outermost layer of the retina, has a key role in maintaining retinal cells’ functions. Severity of the culture of RPE cells has exerted many limitations to both in vitro and in vivo studies and its therapeutic applications. Therefore, establishment of RPE cell lines with high proliferative potential can considerably improve study of RPE cell biology. Here we report generation of a spontaneously immortalized murine RPE cell line in primary mouse RPE cell culture. Founded colonized cells were picked up and expression of RPE and retinal progenitor cells’ (RPC) markers were studied using immunocytochemistry (ICC). Emerged cells cultured over 35 passages and population doubling times in different serum concentrations were calculated. We also investigated the ability of cells for becoming transfected by calcium-phosphate method and for becoming infected by adeno-associated virus serotype 2 (AAV2) using flow cytometry. Data showed that the cobblestone constituent cells expressed RPE65, cytokeratin and ZO1 and moreover several progenitor markers such as Pax6, Sox2, Nestin and Chx10. It revealed that, despite primary RPE cells, the newly emerged cells were easily transfectable and were highly infectable when compared with HEK293T cells. Our data indicated that the emerged mouse RPE cell line pretended RPC-like phenotype and also simultaneously expressed RPE markers. It would be a promising model for leading studies on RPE and RPC cells and substantially confirmed the great RPE plasticity and its invaluable potential in research studies. - Highlights: • Isolation of a spontaneously generated retinal pigmented epithelium cell line is reported. • The cells express some of the retinal progenitor cell markers in addition to the RPE markers. • The aforesaid cell line is highly transfecable and considerably infectable by AAV2. • These results confirm the great RPE plasticity and its invaluable potential in research studies.

Retinal pigmented epithelium (RPE), the outermost layer of the retina, has a key role in maintaining retinal cells’ functions. Severity of the culture of RPE cells has exerted many limitations to both in vitro and in vivo studies and its therapeutic applications. Therefore, establishment of RPE cell lines with high proliferative potential can considerably improve study of RPE cell biology. Here we report generation of a spontaneously immortalized murine RPE cell line in primary mouse RPE cell culture. Founded colonized cells were picked up and expression of RPE and retinal progenitor cells’ (RPC) markers were studied using immunocytochemistry (ICC). Emerged cells cultured over 35 passages and population doubling times in different serum concentrations were calculated. We also investigated the ability of cells for becoming transfected by calcium-phosphate method and for becoming infected by adeno-associated virus serotype 2 (AAV2) using flow cytometry. Data showed that the cobblestone constituent cells expressed RPE65, cytokeratin and ZO1 and moreover several progenitor markers such as Pax6, Sox2, Nestin and Chx10. It revealed that, despite primary RPE cells, the newly emerged cells were easily transfectable and were highly infectable when compared with HEK293T cells. Our data indicated that the emerged mouse RPE cell line pretended RPC-like phenotype and also simultaneously expressed RPE markers. It would be a promising model for leading studies on RPE and RPC cells and substantially confirmed the great RPE plasticity and its invaluable potential in research studies. - Highlights: • Isolation of a spontaneously generated retinal pigmented epithelium cell line is reported. • The cells express some of the retinal progenitor cell markers in addition to the RPE markers. • The aforesaid cell line is highly transfecable and considerably infectable by AAV2. • These results confirm the great RPE plasticity and its invaluable potential in research studies.

Full Text Available Abstract Background The Retinal Pigmented Epithelium (RPE is juxtaposed with the photoreceptor outer segments of the eye. The proximity of the photoreceptor cells is a prerequisite for their survival, as they depend on the RPE to remove the outer segments and are also influenced by RPE cell paracrine factors. RPE cell death can cause a progressive loss of photoreceptor function, which can diminish vision and, over time, blindness ensues. Degeneration of the retina has been shown to induce a variety of retinopathies, such as Stargardt's disease, Cone-Rod Dystrophy (CRD, RetinitisPigmentosa (RP, Fundus Flavimaculatus (FFM, Best's disease and Age-related Macular Degeneration (AMD. We have cultured primary bovine RPE cells to gain a further understanding of the mechanisms of RPE cell death. One of the cultures, named tRPE, surpassed senescence and was further characterized to determine its viability as a model for retinal diseases. Results The tRPE cell line has been passaged up to 150 population doublings and was shown to be morphologically similar to primary cells. They have been characterized to be of RPE origin by reverse transcriptase PCR and immunocytochemistry using the RPE-specific genes RPE65 and CRALBP and RPE-specific proteins RPE65 and Bestrophin. The tRPE cells are also immunoreactive to vimentin, cytokeratin and zonula occludens-1 antibodies. Chromosome analysis indicates a normal diploid number. The tRPE cells do not grow in suspension or in soft agar. After 3H thymidine incorporation, the cells do not appear to divide appreciably after confluency. Conclusion The tRPE cells are immortal, but still exhibit contact inhibition, serum dependence, monolayer growth and secrete an extra-cellular m